The Ethics, by Benedict de Spinoza, [1883], at sacred-texts.com

PART III.

ON THE ORIGIN AND NATURE OF THE EMOTIONS

Most writers on the emotions and on human conduct seem to be treating rather of matters outside nature than of natural phenomena following nature's general laws. They appear to conceive man to be situated in nature as a kingdom within a kingdom: for they believe that he disturbs rather than follows nature's order, that he has absolute control over his actions, and that he is determined solely by himself. They attribute human infirmities and fickleness, not to the power of nature in general, but to some mysterious flaw in the nature of man, which accordingly they bemoan, deride, despise, or, as usually happens, abuse: he, who succeeds in hitting off the weakness of the human mind more eloquently or more acutely than his fellows, is looked upon as a seer. Still there has been no lack of very excellent men (to whose toil and industry I confess myself much indebted), who have written many noteworthy things concerning the right way of life, and have given much sage advice to mankind. But no one, so far as I know, has defined the nature and strength of the emotions, and the power of the mind against them for their restraint.

 I do not forget, that the illustrious Descartes, though he believed, that the mind has absolute power over its actions, strove to explain human emotions by their primary causes, and, at the same time, to point out a way, by which the mind might attain to absolute dominion over them. However, in my opinion, he accomplishes nothing beyond a display of the acuteness of his own great intellect, as I will show in the proper place. For the present I wish to revert to those, who would rather abuse or deride human emotions than understand them. Such persons will, doubtless think it strange that I should attempt to treat of human vice and folly geometrically, and should wish to set forth with rigid reasoning those matters which they cry out against as repugnant to reason, frivolous, absurd, and dreadful. However, such is my plan. Nothing comes to pass in nature, which can be set down to a flaw therein; for nature is always the same, and everywhere one and the same in her efficacy and power of action; that is, nature's laws and ordinances, whereby all things come to pass and change from one form to another, are everywhere and always the same; so that there should be one and the same method of understanding the nature of all things whatsoever, namely, through nature's universal laws and rules. Thus the passions of hatred, anger, envy, and so on, considered in themselves, follow from this same necessity and efficacy of nature; they answer to certain definite causes, through which they are understood, and possess certain properties as worthy of being known as the properties of anything else, whereof the contemplation in itself affords us delight. I shall, therefore, treat of the nature and strength of the emotions according to the same method, as I employed heretofore in my investigations concerning God and the mind. I shall consider human actions and desires in exactly the same manner, as though I were concerned with lines, planes, and solids.

DEFINITIONS

I. By an adequate cause, I mean a cause through which its effect can be clearly and distinctly perceived. By an inadequate or partial cause, I mean a cause through which, by itself, its effect cannot be understood.

II. I say that we act when anything takes place, either within us or externally to us, whereof we are the adequate cause; that is (by the foregoing definition) when through our nature something takes place within us or externally to us, which can through our nature alone be clearly and distinctly understood. On the other hand, I say that we are passive as regards something when that something takes place within us, or follows from our nature externally, we being only the partial cause.

III. By emotion I mean the modifications of the body, whereby the active power of the said body is increased or diminished, aided or constrained, and also the ideas of such modifications.

N.B. If we can be the adequate cause of any of these modifications, I then call the emotion an activity, otherwise I call it a passion, or state wherein the mind is passive.

POSTULATES

I. The human body can be affected in many ways, whereby its power of activity is increased or diminished, and also in other ways which do not render its power of activity either greater or less.

 N.B. This postulate or axiom rests on Postulate i. and Lemmas v. and vii., which see after II. xiii.

II. The human body can undergo many changes, and, nevertheless, retain the impressions or traces of objects (cf. II. Post. v.), and, consequently, the same images of things (see note II. xvii.).

PROP. I. Our mind is in certain cases active, and in certain cases passive. In so far as it has adequate ideas it is necessarily active, and in so far as it has inadequate ideas, it is necessarily passive.

 Proof.—In every human mind there are some adequate ideas, and some ideas that are fragmentary and confused (II. xl. note). Those ideas which are adequate in the mind are adequate also in God, inasmuch as he constitutes the essence of the mind (II. xl. Coroll.), and those which are inadequate in the mind are likewise (by the same Coroll.) adequate in God, not inasmuch as he contains in himself the essence of the given mind alone, but as he, at the same time, contains the minds of other things. Again, from any given idea some effect must necessarily follow (I. 36); of this effect God is the adequate cause (III. Def. i.), not inasmuch as he is infinite, but inasmuch as he is conceived as affected by the given idea (II. ix.). But of that effect whereof God is the cause, inasmuch as he is affected by an idea which is adequate in a given mind, of that effect, I repeat, the mind in question is the adequate cause (II. xi. Coroll.). Therefore our mind, in so far as it has adequate ideas (III. Def. ii.), is in certain cases necessarily active; this was our first point. Again, whatsoever necessarily follows from the idea which is adequate in God, not by virtue of his possessing in himself the mind of one man only, but by virtue of his containing, together with the mind of that one man, the minds of other things also, of such an effect (II. xi. Coroll.) the mind of the given man is not an adequate, but only a partial cause; thus (III. Def. ii.) the mind, inasmuch as it has inadequate ideas, is in certain cases necessarily passive; this was our second point. Therefore our mind, &c. Q.E.D.

 Corollary.—Hence it follows that the mind is more or less liable to be acted upon, in proportion as it possesses inadequate ideas, and, contrariwise, is more or less active in proportion as it possesses adequate ideas.

PROP. II. Body cannot determine mind to think, neither can mind determine body to motion or rest or any state different from these, if such there be.

 Proof.—All modes of thinking have for their cause God, by virtue of his being a thinking thing, and not by virtue of his being displayed under any other attribute (II. vi.). That, therefore, which determines the mind to thought is a mode of thought, and not a mode of extension; that is (II. Def. i.), it is not body. This was our first point. Again, the motion and rest of a body must arise from another body, which has also been determined to a state of motion or rest by a third body, and absolutely everything which takes place in a body must spring from God, in so far as he is regarded as affected by some mode of extension, and not by some mode of thought (II. vi.); that is, it cannot spring from the mind, which is a mode of thought. This was our second point. Therefore body cannot determine mind, &c. Q.E.D.

 Note.—This is made more clear by what was said in the note to II. vii., namely, that mind and body are one and the same thing, conceived first under the attribute of thought, secondly, under the attribute of extension. Thus it follows that the order or concatenation of things is identical, whether nature be conceived under the one attribute or the other; consequently the order of states of activity and passivity in our body is simultaneous in nature with the order of states of activity and passivity in the mind. The same conclusion is evident from the manner in which we proved II. xii.

 Nevertheless, though such is the case, and though there be no further room for doubt, I can scarcely believe, until the fact is proved by experience, that men can be induced to consider the question calmly and fairly, so firmly are they convinced that it is merely at the bidding of the mind, that the body is set in motion or at rest, or performs a variety of actions depending solely on the mind's will or the exercise of thought. However, no one has hitherto laid down the limits to the powers of the body, that is, no one has as yet been taught by experience what the body can accomplish solely by the laws of nature, in so far as she is regarded as extension. No one hitherto has gained such an accurate knowledge of the bodily mechanism, that he can explain all its functions; nor need I call attention to the fact that many actions are observed in the lower animals, which far transcend human sagacity, and that somnambulists do many things in their sleep, which they would not venture to do when awake: these instances are enough to show, that the body can by the sole laws of its nature do many things which the mind wonders at.

 Again, no one knows how or by what means the mind moves the body, nor how many various degrees of motion it can impart to the body, nor how quickly it can move it. Thus, when men say that this or that physical action has its origin in the mind, which latter has dominion over the body, they are using words without meaning, or are confessing in specious phraseology that they are ignorant of the cause of the said action, and do not wonder at it.

 But, they will say, whether we know or do not know the means whereby the mind acts on the body, we have, at any rate, experience of the fact that unless the human mind is in a fit state to think, the body remains inert. Moreover, we have experience, that the mind alone can determine whether we speak or are silent, and a variety of similar states which, accordingly, we say depend on the mind's decree. But, as to the first point, I ask such objectors, whether experience does not also teach, that if the body be inactive the mind is simultaneously unfitted for thinking? For when the body is at rest in sleep, the mind simultaneously is in a state of torpor also, and has no power of thinking, such as it possesses when the body is awake. Again, I think everyone's experience will confirm the statement, that the mind is not at all times equally fit for thinking on a given subject, but according as the body is more or less fitted for being stimulated by the image of this or that object, so also is the mind more or less fitted for contemplating the said object.

 But, it will be urged, it is impossible that solely from the laws of nature considered as extended substance, we should be able to deduce the causes of buildings, pictures, and things of that kind, which are produced only by human art; nor would the human body, unless it were determined and led by the mind, be capable of building a single temple. However, I have just pointed out that the objectors cannot fix the limits of the body's power, or say what can be concluded from a consideration of its sole nature, whereas they have experience of many things being accomplished solely by the laws of nature, which they would never have believed possible except under the direction of mind: such are the actions performed by somnambulists while asleep, and wondered at by their performers when awake. I would further call attention to the mechanism of the human body, which far surpasses in complexity all that has been put together by human art, not to repeat what I have already shown, namely, that from nature, under whatever attribute she be considered, infinite results follow. As for the second objection, I submit that the world would be much happier, if men were as fully able to keep silence as they are to speak. Experience abundantly shows that men can govern anything more easily than their tongues, and restrain anything more easily than their appetites; when it comes about that many believe, that we are only free in respect to objects which we moderately desire, because our desire for such can easily be controlled by the thought of something else frequently remembered, but that we are by no means free in respect to what we seek with violent emotion, for our desire cannot then be allayed with the remembrance of anything else. However, unless such persons had proved by experience that we do many things which we afterwards repent of, and again that we often, when assailed by contrary emotions, see the better and follow the worse, there would be nothing to prevent their believing that we are free in all things. Thus an infant believes that of its own free will it desires milk, an angry child believes that it freely desires vengeance, a timid child believes that it freely desires to run away; further, a drunken man believes that he utters from the free decision of his mind words which, when he is sober, he would willingly have withheld: thus, too, a delirious man, a garrulous woman, a child, and others of like complexion, believe that they speak from the free decision of their mind, when they are in reality unable to restrain their impulse to talk. Experience teaches us no less clearly than reason, that men believe themselves to be free, simply because they are conscious of their actions, and unconscious of the causes whereby those actions are determined; and, further, it is plain that the dictates of the mind are but another name for the appetites, and therefore vary according to the varying state of the body. Everyone shapes his actions according to his emotion, those who are assailed by conflicting emotions know not what they wish; those who are not attacked by any emotion are readily swayed this way or that. All these considerations clearly show that a mental decision and a bodily appetite, or determined state, are simultaneous, or rather are one and the same thing, which we call decision, when it is regarded under and explained through the attribute of thought, and a conditioned state, when it is regarded under the attribute of extension, and deduced from the laws of motion and rest. This will appear yet more plainly in the sequel. For the present I wish to call attention to another point, namely, that we cannot act by the decision of the mind, unless we have a remembrance of having done so. For instance, we cannot say a word without remembering that we have done so. Again, it is not within the free power of the mind to remember or forget a thing at will. Therefore the freedom of the mind must in any case be limited to the power of uttering or not uttering something which it remembers. But when we dream that we speak, we believe that we speak from a free decision of the mind, yet we do not speak, or, if we do, it is by a spontaneous motion of the body. Again, we dream that we are concealing something, and we seem to act from the same decision of the mind as that, whereby we keep silence when awake concerning something we know. Lastly, we dream that from the free decision of our mind we do something, which we should not dare to do when awake.

 Now I should like to know whether there be in the mind two sorts of decisions, one sort illusive, and the other sort free? If our folly does not carry us so far as this, we must necessarily admit, that the decision of the mind, which is believed to be free, is not distinguishable from the imagination or memory, and is nothing more than the affirmation, which an idea, by virtue of being an idea, necessarily involves (II. xlix.). Wherefore these decisions of the mind arise in the mind by the same necessity, as the ideas of things actually existing. Therefore those who believe, that they speak or keep silence or act in any way from the free decision of their mind, do but dream with their eyes open.

PROP. III. The activities of the mind arise solely from adequate ideas; the passive states of the mind depend solely on inadequate ideas.

 Proof.—The first element, which constitutes the essence of the mind, is nothing else but the idea of the actually existent body (II. xi. and xiii.), which (II. xv.) is compounded of many other ideas, whereof some are adequate and some inadequate (II. xxix. Coroll., II. xxxviii. Coroll.). Whatsoever therefore follows from the nature of mind, and has mind for its proximate cause, through which it must be understood, must necessarily follow either from an adequate or from an inadequate idea. But in so far as the mind (III. i.) has inadequate ideas, it is necessarily passive: wherefore the activities of the mind follow solely from adequate ideas, and accordingly the mind is only passive in so far as it has inadequate ideas. Q.E.D.

 Note.—Thus we see, that passive states are not attributed to the mind, except in so far as it contains something involving negation, or in so far as it is regarded as a part of nature, which cannot be clearly and distinctly perceived through itself without other parts: I could thus show, that passive states are attributed to individual things in the same way that they are attributed to the mind, and that they cannot otherwise be perceived, but my purpose is solely to treat of the human mind.

PROP. IV. Nothing can be destroyed, except by a cause external to itself.

 Proof.—This proposition is self-evident, for the definition of anything affirms the essence of that thing, but does not negative it; in other words, it postulates the essence of the thing, but does not take it away. So long therefore as we regard only the thing itself, without taking into account external causes, we shall not be able to find in it anything which could destroy it. Q.E.D.

PROP. V. Things are naturally contrary, that is, cannot exist in the same object, in so far as one is capable of destroying the other.

 Proof.—If they could agree together or co-exist in the same object, there would then be in the said object something which could destroy it; but this, by the foregoing proposition, is absurd, therefore things, &c. Q.E.D.

PROP. VI. Everything, in so far as it is in itself, endeavours to persist in its own being.

 Proof.—Individual things are modes whereby the attributes of God are expressed in a given determinate manner (I. xxv. Coroll.); that is, (I. xxxiv.), they are things which express in a given determinate manner the power of God, whereby God is and acts; now no thing contains in itself anything whereby it can be destroyed, or which can take away its existence (III. iv.); but contrariwise it is opposed to all that could take away its existence (III. v.). Therefore, in so far as it can, and in so far as it is in itself, it endeavours to persist in its own being. Q.E.D.

PROP. VII. The endeavour, wherewith everything endeavours to persist in its own being, is nothing else but the actual essence of the thing in question.

 Proof.—From the given essence of any thing certainconsequences necessarily follow (I. xxxvi.), nor have things any power save such as necessarily follows from their nature as determined (I. xxix.); wherefore the power of any given thing, or the endeavour whereby, either alone or with other things, it acts, or endeavours to act, that is (III. vi.), the power or endeavour, wherewith it endeavours to persist in its own being, is nothing else but the given or actual essence of the thing in question. Q.E.D.

PROP. VIII. The endeavour, whereby a thing endeavours to persist in its own being, involves no finite time, but an indefinite time.

 Proof.—If it involved a limited time, which should determine the duration of the thing, it would then follow solely from that power whereby the thing exists, that the thing could not exist beyond the limits of that time, but that it must be destroyed; but this (III. iv.) is absurd. Wherefore the endeavour wherewith a thing exists involves no definite time; but, contrariwise, since (III. iv.) it will by the same power whereby it already exists always continue to exist, unless it be destroyed by some external cause, this endeavour involves an indefinite time.

PROP. IX. The mind, both in so far as it has clear and distinct ideas, and also in so far as it has confused ideas, endeavours to persist in its being for an indefinite period, and of this endeavour it is conscious.

 Proof.—The essence of the mind is constituted by adequate and inadequate ideas (III. iii.), therefore (III. vii.), both in so far as it possesses the former, and in so far as it possesses the latter, it endeavours to persist in its own being, and that for an indefinite time (III. viii.). Now as the mind (II. xxiii.) is necessarily conscious of itself through the ideas of the modifications of the body, the mind is therefore (III. vii.) conscious of its own endeavour.

 Note.—This endeavour, when referred solely to the mind, is called will, when referred to the mind and body in conjunction it is called appetite; it is, in fact, nothing else but man's essence, from the nature of which necessarily follow all those results which tend to its preservation; and which man has thus been determined to perform.

 Further, between appetite and desire there is no difference, except that the term desire is generally applied to men, in so far as they are conscious of their appetite, and may accordingly be thus defined: Desire is appetite with consciousness thereof. It is thus plain from what has been said, that in no case do we strive for, wish for, long for, or desire anything, because we deem it to be good, but on the other hand we deem a thing to be good, because we strive for it, wish for it, long for it, or desire it.

PROP. X. An idea, which excludes the existence of our body, cannot be postulated in our mind, but is contrary thereto.

 Proof.—Whatsoever can destroy our body, cannot be postulated therein (III. v.). Therefore neither can the idea of such a thing occur in God, in so far as he has the idea of our body (II. ix. Coroll.); that is (II. xi., xiii.), the idea of that thing cannot be postulated as in our mind, but contrariwise, since (II. xi., xiii.) the first element, that constitutes the essence of the mind, is the idea of the human body as actually existing, it follows that the first and chief endeavour of our mind is the endeavour to affirm the existence of our body: thus, an idea, which negatives the existence of our body, is contrary to our mind, &c. Q.E.D.

PROP. XI. Whatsoever increases or diminishes, helps or hinders the power of activity in our body, the idea thereof increases or diminishes, helps or hinders the power of thought in our mind.

 Proof.—This proposition is evident from II. vii. or from II. xiv.

 Note.—Thus we see, that the mind can undergo many changes, and can pass sometimes to a state of greater perfection, sometimes to a state of lesser perfection. These passive states of transition explain to us the emotions of pleasure and pain. By pleasure therefore in the following propositions I shall signify a passive state wherein the mind passes to a greater perfection. By pain I shall signify a passive state wherein the mind passes to a lesser perfection. Further, the emotion of pleasure in reference to the body and mind together I shall call stimulation (titillatio) or merriment (hilaritas), the emotion of pain in the same relation I shall call suffering or melancholy. But we must bear in mind, that stimulation and suffering are attributed to man, when one part of his nature is more affected than the rest, merriment and melancholy, when all parts are alike affected. What I mean by desire I have explained in the note to Prop. ix. of this part; beyond these three I recognize no other primary emotion; I will show as I proceed, that all other emotions arise from these three. But, before I go further, I should like here to explain at greater length Prop. x of this part, in order that we may clearly understand how one idea is contrary to another. In the note to II. xvii. we showed that the idea, which constitutes the essence of mind, involves the existence of body, so long as the body itself exists. Again, it follows from what we pointed out in the Corollary to II. viii., that the present existence of our mind depends solely on the fact, that the mind involves the actual existence of the body. Lastly, we showed (II. xvii., xviii. and note) that the power of the mind, whereby it imagines and remembers things, also depends on the fact, that it involves the actual existence of the body. Whence it follows, that the present existence of the mind and its power of imagining are removed, as soon as the mind ceases to affirm the present existence of the body. Now the cause, why the mind ceases to affirm this existence of the body, cannot be the mind itself (III. iv.), nor again the fact that the body ceases to exist. For (by II. vi.) the cause, why the mind affirms the existence of the body, is not that the body began to exist; therefore, for the same reason, it does not cease to affirm the existence of the body, because the body ceases to exist; but (II. xvii.) this result follows from another idea, which excludes the present existence of our body and, consequently, of our mind, and which is therefore contrary to the idea constituting the essence of our mind.

PROP. XII. The mind, as far as it can, endeavours to conceive those things, which increase or help the power of activity in the body.

 Proof.—So long as the human body is affected in a mode, which involves the nature of any external body, the human mind will regard that external body as present (II. xvii.), and consequently (II. vii.), so long as the human mind regards an external body as present, that is (II. xvii. note), conceives it, the human body is affected in a mode, which involves the nature of the said external body; thus so long as the mind conceives things, which increase or help the power of activity in our body, the body is affected in modes which increase or help its power of activity (III. Post. i.); consequently (III. xi.) the mind's power of thinking is for that period increased or helped. Thus (III. vi., ix.) the mind, as far as it can, endeavours to imagine such things. Q.E.D.

PROP. XIII. When the mind conceives things which diminish or hinder the body's power of activity, it endeavours, as far as possible, to remember things which exclude the existence of the first-named things.

 Proof.—So long as the mind conceives anything of the kind alluded to, the power of the mind and body is diminished or constrained (cf. III. xii. Proof); nevertheless it will continue to conceive it, until the mind conceives something else, which excludes the present existence thereof (II. xvii.); that is (as I have just shown), the power of the mind and of the body is diminished, or constrained, until the mind conceives something else, which excludes the existence of the former thing conceived: therefore the mind (III. ix.), as far as it can, will endeavour to conceive or remember the latter. Q.E.D.

 Corollary.—Hence it follows that the mind shrinks from conceiving those things, which diminish or constrain the power of itself and of the body.

 Note.—From what has been said we may clearly understand the nature of Love and Hate. Love is nothing else but pleasure accompanied by the idea of an external cause: Hate is nothing else but pain accompanied by the idea of an external cause. We further see, that he who loves necessarily endeavours to have, and to keep present to him, the object of his love; while he who hates endeavours to remove and destroy the object of his hatred. But I will treat of these matters at more length hereafter.

PROP. XIV. If the mind has once been affected by two emotions at the same time, it will, whenever it is afterwards affected by one of these two, be also affected by the other.

 Proof.—If the human body has once been affected by two bodies at once, whenever afterwards the mind conceives one of them, it will straightway remember the other also (II. xviii.). But the mind's conceptions indicate rather the emotions of our body than the nature of external bodies (II. xvi. Coroll. ii.); therefore, if the body, and consequently the mind (III. Def. iii.) has been once affected by two emotions at the same time, it will, whenever it is afterwards affected by one of the two, be also affected by the other.

PROP. XV. Anything can, accidentally, be the cause of pleasure, pain, or desire.

 Proof.—Let it be granted that the mind is simultaneously affected by two emotions, of which one neither increases nor diminishes its power of activity, and the other does either increase or diminish the said power (III. Post. i.). From the foregoing proposition it is evident that, whenever the mind is afterwards affected by the former, through its true cause, which (by hypothesis) neither increases nor diminishes its power of action, it will be at the same time affected by the latter, which does increase or diminish its power of activity, that is (III. xi. note) it will be affected with pleasure or pain. Thus the former of the two emotions will, not through itself, but accidentally, be the cause of pleasure or pain. In the same way also it can be easily shown, that a thing may be accidentally the cause of desire. Q.E.D.

 Corollary.—Simply from the fact that we have regarded a thing with the emotion of pleasure or pain, though that thing be not the efficient cause of the emotion, we can either love or hate it.

 Proof.—For from this fact alone it arises (III. xiv.), that the mind afterwards conceiving the said thing is affected with the emotion of pleasure or pain, that is (III. xi. note), according as the power of the mind and body may be increased or diminished, &c.; and consequently (III. xii.), according as the mind may desire or shrink from the conception of it (III. xiii. Coroll.), in other words (III. xiii. note), according as it may love or hate the same. Q.E.D.

 Note.—Hence we understand how it may happen, that we love or hate a thing without any cause for our emotion being known to us; merely, as a phrase is, from sympathy or antipathy. We should refer to the same category those objects, which affect us pleasurably or painfully, simply because they resemble other objects which affect us in the same way. This I will show in the next Prop. I am aware that certain authors, who were the first to introduce these terms "sympathy" and "antipathy," wished to signify thereby some occult qualities in things; nevertheless I think we may be permitted to use the same terms to indicate known or manifest qualities.

PROP. XVI. Simply from the fact that we conceive, that a given object has some point of resemblance with another object which is wont to affect the mind pleasurably or painfully, although the point of resemblance be not the efficient cause of the said emotions, we shall still regard the first-named object with love or hate.

 Proof.—The point of resemblance was in the object (by hypothesis), when we regarded it with pleasure or pain, thus (III. xiv.), when the mind is affected by the image thereof, it will straightway be affected by one or the other emotion, and consequently the thing, which we perceive to have the same point of resemblance, will be accidentally (III. xv.) a cause of pleasure or pain. Thus (by the foregoing Corollary), although the point in which the two objects resemble one another be not the efficient cause of the emotion, we shall still regard the first-named object with love or hate. Q.E.D.

PROP. XVII. If we conceive that a thing, which is wont to affect us painfully, has any point of resemblance with another thing which is wont to affect us with an equally strong emotion of pleasure, we shall hate the first-named thing, and at the same time we shall love it.

 Proof.—The given thing is (by hypothesis) in itself a cause of pain, and (III. xiii. note), in so far as we imagine it with this emotion, we shall hate it: further, inasmuch as we conceive that it has some point of resemblance to something else, which is wont to affect us with an equally strong emotion of pleasure, we shall with an equally strong impulse of pleasure love it (III.xvi.); thus we shall both hate and love the same thing. Q.E.D.

 Note.—This disposition of the mind, which arises from two contrary emotions, is called vacillation; it stands to the emotions in the same relation as doubt does to the imagination (II. xliv. note); vacillation and doubt do not differ one from the other, except as greater differs from less. But we must bear in mind that I have deduced this vacillation from causes, which give rise through themselves to one of the emotions, and to the other accidentally. I have done this, in order that they might be more easily deduced from what went before; but I do not deny that vacillation of the disposition generally arises from an object, which is the efficient cause of both emotions. The human body is composed (II. Post. i.) of a variety of individual parts of different nature, and may therefore (Ax.i. after Lemma iii. after II. xiii.) be affected in a variety of different ways by one and the same body; and contrariwise, as one and the same thing can be affected in many ways, it can also in many different ways affect one and the same part of the body. Hence we can easily conceive, that one and the same object may be the cause of many and conflicting emotions.

PROP. XVIII. A man is as much affected pleasurably or painfully by the image of a thing past or future as by the image of a thing present.

 Proof.—So long as a man is affected by the image of anything, he will regard that thing as present, even though it be non-existent (II. xvii. and Coroll.), he will not conceive it as past or future, except in so far as its image is joined to the image of time past or future (II. xliv. note). Wherefore the image of a thing, regarded in itself alone, is identical, whether it be referred to time past, time future, or time present; that is (II. xvi. Coroll.), the disposition or emotion of the body is identical, whether the image be of a thing past, future, or present. Thus the emotion of pleasure or pain is the same, whether the image be of a thing past or future. Q.E.D.

 Note I.—I call a thing past or future, according as we either have been or shall be affected thereby. For instance, according as we have seen it, or are about to see it, according as it has recreated us, or will recreate us, according as it has harmed us, or will harm us. For, as we thus conceive it, we affirm its existence; that is, the body is affected by no emotion which excludes the existence of the thing, and therefore (II. xvii.) the body is affected by the image of the thing, in the same way as if the thing were actually present. However, as it generally happens that those, who have had many experiences, vacillate, so long as they regard a thing as future or past, and are usually in doubt about its issue (II. xliv. note); it follows that the emotions which arise from similar images of things are not so constant, but are generally disturbed by the images of other things, until men become assured of the issue.

 Note II.—From what has just been said, we understand what is meant by the terms Hope, Fear, Confidence, Despair, Joy, and Disappointment.5 Hope is nothing else but an inconstant pleasure, arising from the image of something future or past, whereof we do not yet know the issue. Fear, on the other hand, is an inconstant pain also arising from the image of something concerning which we are in doubt. If the element of doubt be removed from these emotions, hope becomes Confidence and fear becomes Despair. In other words, Pleasure or Pain arising from the image of something concerning which we have hoped or feared. Again, Joy is Pleasure arising from the image of something past whereof we have doubted the issue. Disappointment is the Pain opposed to Joy.

PROP. XIX. He who conceives that the object of his love is destroyed will feel pain; if he conceives that it is preserved he will feel pleasure.

 Proof.—The mind, as far as possible, endeavours to conceive those things which increase or help the body's power of activity (III. xii.); in other words (III. xii. note), those things which it loves. But conception is helped by those things which postulate the existence of a thing, and contrariwise is hindered by those which exclude the existence of a thing (II. xvii.); therefore the images of things, which postulate the existence of an object of love, help the mind's endeavour to conceive the object of love, in other words (III. xi. note), affect the mind pleasurably; contrariwise those things, which exclude the existence of an object of love, hinder the aforesaid mental endeavour; in other words, affect the mind painfully. He, therefore, who conceives that the object of his love is destroyed will feel pain, &c. Q.E.D.

PROP. XX. He who conceives that the object of his hate is destroyed will also feel pleasure.

 Proof.—The mind (III. xiii.) endeavours to conceive those things, which exclude the existence of things whereby the body's power of activity is diminished or constrained; that is (III. xiii. note), it endeavours to conceive such things as exclude the existence of what it hates; therefore the image of a thing, which excludes the existence of what the mind hates, helps the aforesaid mental effort, in other words (III. xi. note), affects the mind pleasurably. Thus he who conceives that the object of his hate is destroyed will feel pleasure. Q.E.D.

PROP. XXI. He who conceives, that the object of his love is affected pleasurably or painfully, will himself be affected pleasurably or painfully; and the one or the other emotion will be greater or less in the lover according as it is greater or less in the thing loved.

 Proof.—The images of things (as we showed in III. xix.) which postulate the existence of the object of love, help the mind's endeavour to conceive the said object. But pleasure postulates the existence of something feeling pleasure, so much the more in proportion as the emotion of pleasure is greater; for it is (III. xi. note) a transition to a greater perfection; therefore the image of pleasure in the object of love helps the mental endeavour of the lover; that is, it affects the lover pleasurably, and so much the more, in proportion as this emotion may have been greater in the object of love. This was our first point. Further, in so far as a thing is affected with pain, it is to that extent destroyed, the extent being in proportion to the amount of pain (III. xi. note); therefore (III. xix.) he who conceives, that the object of his love is affected painfully, will himself be affected painfully, in proportion as the said emotion is greater or less in the object of love. Q.E.D.

PROP. XXII. If we conceive that anything pleasurably affects some object of our love, we shall be affected with love towards that thing. Contrariwise, if we conceive that it affects an object of our love painfully, we shall be affected with hatred towards it.

 Proof.—He, who affects pleasurably or painfully the object of our love, affects us also pleasurably or painfully-that is, if we conceive the loved object as affected with the said pleasure or pain (III. xxi.). But this pleasure or pain is postulated to come to us accompanied by the idea of an external cause; therefore (III. xiii. note), if we conceive that anyone affects an object of our love pleasurably or painfully, we shall be affected with love or hatred towards him. Q.E.D.

 Note.—Prop. xxi. explains to us the nature of Pity, which we may define as pain arising from another's hurt. What term we can use for pleasure arising from another's gain, I know not.

 We will call the love towards him who confers a benefit on another, Approval; and the hatred towards him who injures another, we will call Indignation. We must further remark, that we not only feel pity for a thing which we have loved (as shown in III. xxi.), but also for a thing which we have hitherto regarded without emotion, provided that we deem that it resembles ourselves (as I will show presently). Thus, we bestow approval on one who has benefited anything resembling ourselves, and, contrariwise, are indignant with him who has done it an injury.

PROP. XXIII. He who conceives, that an object of his hatred is painfully affected, will feel pleasure. Contrariwise, if he thinks that the said object is pleasurably affected, he will feel pain. Each of these emotions will be greater or less, according as its contrary is greater or less in the object of hatred.

 Proof.—In so far as an object of hatred is painfully affected, it is destroyed, to an extent proportioned to the strength of the pain (III. xi. note). Therefore, he (III. xx.) who conceives, that some object of his hatred is painfully affected, will feel pleasure, to an extent proportioned to the amount of pain he conceives in the object of his hatred. This was our first point. Again, pleasure postulates the existence of the pleasurably affected thing (III. xi. note), in proportion as the pleasure is greater or less. If anyone imagines that an object of his hatred is pleasurably affected, this conception (III. xiii.) will hinder his own endeavour to persist; in other words (III. xi. note), he who hates will be painfully affected. Q.E.D.

 Note.—This pleasure can scarcely be felt unalloyed, and without any mental conflict. For (as I am about to show in Prop. xxvii.), in so far as a man conceives that something similar to himself is affected by pain, he will himself be affected in like manner; and he will have the contrary emotion in contrary circumstances. But here we are regarding hatred only.

PROP. XXIV. If we conceive that anyone pleasurably affects an object of our hate, we shall feel hatred towards him also. If we conceive that he painfully affects that said object, we shall feel love towards him.

 Proof.—This proposition is proved in the same way as III. xxii., which see.

 Note.—These and similar emotions of hatred are attributable to envy, which, accordingly, is nothing else but hatred, in so far as it is regarded as disposing a man to rejoice in another's hurt, and to grieve at another's advantage.

PROP. XXV. We endeavour to affirm, concerning ourselves, and concerning what we love, everything that we can conceive to affect pleasurably ourselves, or the loved object. Contrariwise, we endeavour to negative everything, which we conceive to affect painfully ourselves or the loved object.

 Proof.—That, which we conceive to affect an object of our love pleasurably or painfully, affects us also pleasurably or painfully (III. xxi.). But the mind (III. xii.) endeavours, as far as possible, to conceive those things which affect us pleasurably; in other words (II. xvii. and Coroll.), it endeavours to regard them as present. And, contrariwise (III. xiii.), it endeavours to exclude the existence of such things as affect us painfully; therefore, we endeavour to affirm concerning ourselves, and concerning the loved object, whatever we conceive to affect ourselves, or the love object pleasurably. Q.E.D.

PROP. XXVI. We endeavour to affirm, concerning that which we hate, everything which we conceive to affect it painfully; and, contrariwise, we endeavour to deny, concerning it, everything which we conceive to affect it pleasurably.

 Proof.—This proposition follows from III. xxiii., as thefore going proposition followed from III. xxi.

 Note.—Thus we see that it may readily happen, that a man may easily think too highly of himself, or a loved object, and, contrariwise, too meanly of a hated object. This feeling is called pride, in reference to the man who thinks too highly of himself, and is a species of madness, wherein a man dreams with his eyes open, thinking that he can accomplish all things that fall within the scope of his conception, and thereupon accounting them real, and exulting in them, so long as he is unable to conceive anything which excludes their existence, and determines his own power of action. Pride, therefore, is pleasure springing from a man thinking too highly of himself. Again, the pleasure which arises from a man thinking too highly of another is called over-esteem. Whereas the pleasure which arises from thinking too little of a man is called disdain.

PROP. XXVII. By the very fact that we conceive a thing, which is like ourselves, and which we have not regarded with any emotion, to be affected with any emotion, we are ourselves affected with a like emotion (affectus).

 Proof.—The images of things are modifications of the human body, whereof the ideas represent external bodies as present to us (II. xvii.); in other words (II. x.), whereof the ideas involve the nature of our body, and, at the same time, the nature of the external bodies as present. If, therefore, the nature of the external body be similar to the nature of our body, then the idea which we form of the external body will involve a modification of our own body similar to the modification of the external body. Consequently, if we conceive anyone similar to ourselves as affected by any emotion, this conception will express a modification of our body similar to that emotion. Thus, from the fact of conceiving a thing like ourselves to be affected with any emotion, we are ourselves affected with a like emotion. If, however, we hate the said thing like ourselves, we shall, to that extent, be affected by a contrary, and not similar, emotion. Q.E.D.

 Note I.—This imitation of emotions, when it is referred to pain, is called compassion (cf. III. xxii. note); when it is referred to desire, it is called emulation, which is nothing else but the desire of anything, engendered in us by the fact that we conceive that others have the like desire.

 Corollary I.—If we conceive that anyone, whom we have hitherto regarded with no emotion, pleasurably affects something similar to ourselves, we shall be affected with love towards him. If, on the other hand, we conceive that he painfully affects the same, we shall be affected with hatred towards him.

 Proof.—This is proved from the last proposition in the same manner as III. xxii. is proved from III. xxi.

 Corollary II.—We cannot hate a thing which we pity, because its misery affects us painfully.

 Proof.—If we could hate it for this reason, we should rejoice in its pain, which is contrary to the hypothesis.

 Corollary III.—We seek to free from misery, as far as we can, a thing which we pity.

 Proof.—That, which painfully affects the object of our pity, affects us also with similar pain (by the foregoing proposition); therefore, we shall endeavour to recall everything which removes its existence, or which destroys it (cf. III. xiii.); in other words (III. ix. note), we shall desire to destroy it, or we shall be determined for its destruction; thus, we shall endeavour to free from misery a thing which we pity. Q.E.D.

 Note II.—This will or appetite for doing good, which arises from pity of the thing whereon we would confer a benefit, is called benevolence, and is nothing else but desire arising from compassion. Concerning love or hate towards him who has done good or harm to something, which we conceive to be like ourselves, see III. xxii. note.

PROP. XXVIII. We endeavour to bring about whatsoever we conceive to conduce to pleasure; but we endeavour to remove or destroy whatsoever we conceive to be truly repugnant thereto, or to conduce to pain.

 Proof.—We endeavour, as far as possible, to conceive that which we imagine to conduce to pleasure (III. xii.); in other words (II. xvii.) we shall endeavour to conceive it as far as possible as present or actually existing. But the endeavour of the mind, or the mind's power of thought, is equal to, and simultaneous with, the endeavour of the body, or the body's power of action. (This is clear from II. vii. Coroll. and II. xi. Coroll.). Therefore we make an absolute endeavour for its existence, in other words (which by III. ix. note, come to the same thing) we desire and strive for it; this was our first point. Again, if we conceive that something, which we believed to be the cause of pain, that is (III. xiii. note), which we hate, is destroyed, we shall rejoice (III. xx.). We shall, therefore (by the first part of this proof), endeavour to destroy the same, or (III. xiii.) to remove it from us, so that we may not regard it as present; this was our second point. Wherefore whatsoever conduces to pleasure, &c. Q.E.D.

PROP. XXIX. We shall also endeavour to do whatsoever we conceive men 6 to regard with pleasure, and contrariwise we shall shrink from doing that which we conceive men to shrink from.

 Proof.—From the fact of imagining, that men love or hate anything, we shall love or hate the same thing (III. xxvii.). That is (III. xiii. note), from this mere fact we shall feel pleasure or pain at the thing's presence. And so we shall endeavour to do whatsoever we conceive men to love or regard with pleasure, etc. Q.E.D.

 Note.—This endeavour to do a thing or leave it undone, solely in order to please men, we call ambition, especially when we so eagerly endeavour to please the vulgar, that we do or omit certain things to our own or another's hurt: in other cases it is generally called kindliness. Furthermore I give the name of praise to the pleasure, with which we conceive the action of another, whereby he has endeavoured to please us; but of blame to the pain wherewith we feel aversion to his action.

PROP. XXX. If anyone has done something which he conceives as affecting other men pleasurably, he will be affected by pleasure, accompanied by the idea of himself as cause; in other words, he will regard himself with pleasure. On the other hand, if he has done anything which he conceives as affecting others painfully, he will regard himself with pain.

 Proof.—He who conceives, that he affects others with pleasure or pain, will, by that very fact, himself be affected with pleasure or pain (III. xxvii.), but, as a man (II. xix. and xxiii.) is conscious of himself through the modifications whereby he is determined to action, it follows that he who conceives, that he affects others pleasurably, will be affected with pleasure accompanied by the idea of himself as cause; in other words, he will regard himself with pleasure. And so mutatis mutandis in the case of pain. Q.E.D.

 Note.—As love (III. xiii.) is pleasure accompanied by the idea of an external cause, and hatred is pain accompanied by the idea of an external cause; the pleasure and pain in question will be a species of love and hatred. But, as the terms love and hatred are used in reference to external objects, we will employ other names for the emotions now under discussion: pleasure accompanied by the idea of an external cause7 we will style Honour, and the emotion contrary thereto we will style Shame: I mean in such cases as where pleasure or pain arises from a man's belief, that he is being praised or blamed: otherwise pleasure accompanied by the idea of an external cause8 is called self-complacency, and its contrary pain is called repentance. Again, as it may happen (II. xvii. Coroll.) that the pleasure, wherewith a man conceives that he affects others, may exist solely in his own imagination, and as (III. xxv.) everyone endeavours to conceive concerning himself that which he conceives will affect him with pleasure, it may easily come to pass that a vain man may be proud and may imagine that he is pleasing to all, when in reality he may be an annoyance to all.

PROP. XXXI. If we conceive that anyone loves, desires, or hates anything which we ourselves love, desire, or hate, we shall thereupon regard the thing in question with more steadfast love, &c. On the contrary, if we think that anyone shrinks from something that we love, we shall undergo vacillations of soul.

 Proof.—From the mere fact of conceiving that anyone loves anything we shall ourselves love that thing (III. xxvii.): but we are assumed to love it already; there is, therefore, a new cause of love, whereby our former emotion is fostered; hence we shall thereupon love it more steadfastly. Again, from the mere fact of conceiving that anyone shrinks from anything, we shall ourselves shrink from that thing (III. xxvii.). If we assume that we at the same time love it, we shall then simultaneously love it and shrink from it; in other words, we shall be subject to vacillation (III. xvii. note). Q.E.D.

 Corollary.—From the foregoing, and also from III. xxviii. it follows that everyone endeavours, as far as possible, to cause others to love what he himself loves, and to hate what he himself hates: as the poet says: "As lovers let us share every hope and every fear: ironhearted were he who should love what the other leaves."9

 Note.—This endeavour to bring it about, that our own likes and dislikes should meet with universal approval, is really ambition (see III. xxix. note); wherefore we see that everyone by nature desires (appetere), that the rest of mankind should live according to his own individual disposition: when such a desire is equally present in all, everyone stands in everyone else's way, and in wishing to be loved or praised by all, all become mutually hateful.

PROP. XXXII. If we conceive that anyone takes delight in something, which only one person can possess, we shall endeavour to bring it about that the man in question shall not gain possession thereof.

 Proof.—From the mere fact of our conceiving that another person takes delight in a thing (III. xxvii. and Coroll.) we shall ourselves love that thing and desire to take delight therein. But we assumed that the pleasure in question would be prevented by another's delight in its object; we shall, therefore, endeavour to prevent his possession thereof (III. xxviii.). Q.E.D.

 Note.—We thus see that man's nature is generally so constituted, that he takes pity on those who fare ill, and envies those who fare well with an amount of hatred proportioned to his own love for the goods in their possession. Further, we see that from the same property of human nature, whence it follows that men are merciful, it follows also that they are envious and ambitious. Lastly, if we make appeal to Experience, we shall find that she entirely confirms what we have said; more especially if we turn our attention to the first years of our life. We find that children, whose body is continually, as it were, in equilibrium, laugh or cry simply because they see others laughing or crying; moreover, they desire forthwith to imitate whatever they see others doing, and to possess themselves of whatever they conceive as delighting others: inasmuch as the images of things are, as we have said, modifications of the human body, or modes wherein the human body is affected and disposed by external causes to act in this or that manner.

PROP. XXXIII. When we love a thing similar to ourselves we endeavour, as far as we can, to bring about that it should love us in return.

 Proof.—That which we love we endeavour, as far as we can, to conceive in preference to anything else (III. xii.). If the thing be similar to ourselves, we shall endeavour to affect it pleasurably in preference to anything else (III. xxix.). In other words, we shall endeavour, as far as we can, to bring it about, that the thing should be affected with pleasure accompanied by the idea of ourselves, that is (III. xiii. note), that it should love us in return. Q.E.D.

PROP. XXXIV. The greater the emotion with which we conceive a loved object to be affected towards us, the greater will be our complacency.

 Proof.—We endeavour (III. xxxiii.), as far as we can, to bring about, that what we love should love us in return: in other words, that what we love should be affected with pleasure accompanied by the idea of ourself as cause. Therefore, in proportion as the loved object is more pleasurably affected because of us, our endeavour will be assisted.—that is (III. xi. and note) the greater will be our pleasure. But when we take pleasure in the fact, that we pleasurably affect something similar to ourselves, we regard ourselves with pleasure (III. 30); therefore the greater the emotion with which we conceive a loved object to be affected, &c. Q.E.D.

PROP. XXXV. If anyone conceives, that an object of his love joins itself to another with closer bonds of friendship than he himself has attained to, he will be affected with hatred towards the loved object and with envy towards his rival.

 Proof.—In proportion as a man thinks, that a loved object is well affected towards him, will be the strength of his self-approval (by the last Prop.), that is (III. xxx. note), of his pleasure; he will, therefore (III. xxviii.), endeavour, as far as he can, to imagine the loved object as most closely bound to him: this endeavour or desire will be increased, if he thinks that someone else has a similar desire (III. xxxi.). But this endeavour or desire is assumed to be checked by the image of the loved object in conjunction with the image of him whom the loved object has joined to itself; therefore (III. xi. note) he will for that reason be affected with pain, accompanied by the idea of the loved object as a cause in conjunction with the image of his rival; that is, he will be (III. xiii.) affected with hatred towards the loved object and also towards his rival (III. xv. Coroll.), which latter he will envy as enjoying the beloved object. Q.E.D.

 Note.—This hatred towards an object of love joined with envy is called Jealousy, which accordingly is nothing else but a wavering of the disposition arising from combined love and hatred, accompanied by the idea of some rival who is envied. Further, this hatred towards the object of love will be greater, in proportion to the pleasure which the jealous man had been wont to derive from the reciprocated love of the said object; and also in proportion to the feelings he had previously entertained towards his rival. If he had hated him, he will forthwith hate the object of his love, because he conceives it is pleasurably affected by one whom he himself hates: and also because he is compelled to associate the image of his loved one with the image of him whom he hates. This condition generally comes into play in the case of love for a woman: for he who thinks, that a woman whom he loves prostitutes herself to another, will feel pain, not only because his own desire is restrained, but also because, being compelled to associate the image of her he loves with the parts of shame and the excreta of another, he therefore shrinks from her.

 We must add, that a jealous man is not greeted by his beloved with the same joyful countenance as before, and this also gives him pain as a lover, as I will now show.

PROP. XXXVI. He who remembers a thing, in which he has once taken delight, desires to possess it under the same circumstances as when he first took delight therein.

 Proof.—Everything, which a man has seen in conjunction with the object of his love, will be to him accidentally a cause of pleasure (III. xv.); he will, therefore, desire to possess it, in conjunction with that wherein he has taken delight; in other words, he will desire to possess the object of his love under the same circumstances as when he first took delight therein. Q.E.D.

 Corollary.—A lover will, therefore, feel pain if one of theaforesaid attendant circumstances be missing.

 Proof.—For, in so far as he finds some circumstance to be missing, he conceives something which excludes its existence. As he is assumed to be desirous for love's sake of that thing or circumstance (by the last Prop.), he will, in so far as he conceives it to be missing, feel pain (III. xix.). Q.E.D.

 Note.—This pain, in so far as it has reference to the absence of the object of love, is called Regret.

PROP. XXXVII. Desire arising through pain or pleasure, hatred or love, is greater in proportion as the emotion is greater.

 Proof.—Pain diminishes or constrains a man's power of activity (III. xi. note), in other words (III. vii.), diminishes or constrains the effort, wherewith he endeavours to persist in his own being; therefore (III. v.) it is contrary to the said endeavour: thus all the endeavours of a man affected by pain are directed to removing that pain. But (by the definition of pain), in proportion as the pain is greater, so also is it necessarily opposed to a greater part of man's power of activity; therefore the greater the pain, the greater the power of activity employed to remove it; that is, the greater will be the desire or appetite in endeavouring to remove it. Again, since pleasure (III. xi. note) increases or aids a man's power of activity, it may easily be shown in like manner, that a man affected by pleasure has no desire further than to preserve it, and his desire will be in proportion to the magnitude of the pleasure.

 Lastly, since hatred and love are themselves emotions of pain and pleasure, it follows in like manner that the endeavour, appetite, or desire, which arises through hatred or love, will be greater in proportion to the hatred or love. Q.E.D.

PROP. XXXVIII. If a man has begun to hate an object of his love, so that love is thoroughly destroyed, he will, causes being equal, regard it with more hatred than if he had never loved it, and his hatred will be in proportion to the strength of his former love.

 Proof.—If a man begins to hate that which he had loved, more of his appetites are put under restraint than if he had never loved it. For love is a pleasure (III. xiii. note) which a man endeavours as far as he can to render permanent (III. xxviii.); he does so by regarding the object of his love as present, and by affecting it as far as he can pleasurably; this endeavour is greater in proportion as the love is greater, and so also is the endeavour to bring about that the beloved should return his affection (III. xxxiii.). Now these endeavours are constrained by hatred towards the object of love (III. xiii. Coroll. and III. xxiii.); wherefore the lover (III. xi. note) will for this cause also be affected with pain, the more so in proportion as his love has been greater; that is, in addition to the pain caused by hatred, there is a pain caused by the fact that he has loved the object; wherefore the lover will regard the beloved with greater pain, or in other words, will hate it more than if he had never loved it, and with the more intensity in proportion as his former love was greater. Q.E.D.

PROP. XXXIX. He who hates anyone will endeavour to do him an injury, unless he fears that a greater injury will thereby accrue to himself; on the other hand, he who loves anyone will, by the same law, seek to benefit him.

 Proof.—To hate a man is (III. xiii. note) to conceive him as a cause of pain; therefore he who hates a man will endeavour to remove or destroy him. But if anything more painful, or, in other words, a greater evil, should accrue to the hater thereby-and if the hater thinks he can avoid such evil by not carrying out the injury, which he planned against the object of his hate-he will desire to abstain from inflicting that injury (III. xxviii.), and the strength of his endeavour (III. xxxvii.) will be greater than his former endeavour to do injury, and will therefore prevail over it, as we asserted. The second part of this proof proceeds in the same manner. Wherefore he who hates another, etc. Q.E.D.

 Note.—By good I here mean every kind of pleasure, and all that conduces thereto, especially that which satisfies our longings, whatsoever they may be. By evil, I mean every kind of pain, especially that which frustrates our longings. For I have shown (III. ix. note) that we in no case desire a thing because we deem it good, but, contrariwise, we deem a thing good because we desire it: consequently we deem evil that which we shrink from; everyone, therefore, according to his particular emotions, judges or estimates what is good, what is bad, what is better, what is worse, lastly, what is best, and what is worst. Thus a miser thinks that abundance of money is the best, and want of money the worst; an ambitious man desires nothing so much as glory, and fears nothing so much as shame. To an envious man nothing is more delightful than another's misfortune, and nothing more painful than another's success. So every man, according to his emotions, judges a thing to be good or bad, useful or useless. The emotion, which induces a man to turn from that which he wishes, or to wish for that which he turns from, is called timidity, which may accordingly be defined as the fear whereby a man is induced to avoid an evil which he regards as future by encountering a lesser evil (III. xxviii.). But if the evil which he fears be shame, timidity becomes bashfulness. Lastly, if the desire to avoid a future evil be checked by the fear of another evil, so that the man knows not which to choose, fear becomes consternation, especially if both the evils feared be very great.

PROP. XL. He, who conceives himself to be hated by another, and believes that he has given him no cause for hatred, will hate that other in return.

 Proof.—He who conceives another as affected with hatred, will thereupon be affected himself with hatred (III. xxvii.), that is, with pain, accompanied by the idea of an external cause. But, by the hypothesis, he conceives no cause for this pain except him who is his enemy; therefore, from conceiving that he is hated by some one, he will be affected with pain, accompanied by the idea of his enemy; in other words, he will hate his enemy in return. Q.E.D.

 Note.—He who thinks that he has given just cause for hatred will (III. xxx. and note) be affected with shame; but this case (III. xxv.) rarely happens. This reciprocation of hatred may also arise from the hatred, which follows an endeavour to injure the object of our hate (III. xxxix.). He therefore who conceives that he is hated by another will conceive his enemy as the cause of some evil or pain; thus he will be affected with pain or fear, accompanied by the idea of his enemy as cause; in other words, he will be affected with hatred towards his enemy, as I said above.

 Corollary I.—He who conceives, that one whom he loves hates him, will be a prey to conflicting hatred and love. For, in so far as he conceives that he is an object of hatred, he is determined to hate his enemy in return. But, by the hypothesis, he nevertheless loves him: wherefore he will be a prey to conflicting hatred and love.

 Corollary II.—If a man conceives that one, whom he has hitherto regarded without emotion, has done him any injury from motives of hatred, he will forthwith seek to repay the injury in kind.

 Proof.—He who conceives, that another hates him, will (by the last proposition) hate his enemy in return, and (III. xxvi.) will endeavour to recall everything which can affect him painfully; he will moreover endeavour to do him an injury (III. xxxix.). Now the first thing of this sort which he conceives is the injury done to himself; he will, therefore, forthwith endeavour to repay it in kind. Q.E.D.

 Note.—The endeavour to injure one whom we hate is called Anger; the endeavour to repay in kind injury done to ourselves is called Revenge.

PROP. XLI. If anyone conceives that he is loved by another, and believes that he has given no cause for such love, he will love that other in return. (Cf. III. xv. Coroll., and III. xvi.)

 Proof.—This proposition is proved in the same way as the preceding one. See also the note appended thereto.

 Note.—If he believes that he has given just cause for the love, he will take pride therein (III. xxx. and note); this is what most often happens (III. xxv.), and we said that its contrary took place whenever a man conceives himself to be hated by another. (See note to preceding proposition.) This reciprocal love, and consequently the desire of benefiting him who loves us (III. xxxix.), and who endeavours to benefit us, is called gratitude or thankfulness. It thus appears that men are much more prone to take vengeance than to return benefits.

 Corollary.—He who imagines that he is loved by one whom he hates, will be a prey to conflicting hatred and love. This is proved in the same way as the first corollary of the preceding proposition.

 Note.—If hatred be the prevailing emotion, he will endeavour to injure him who loves him; this emotion is called cruelty, especially if the victim be believed to have given no ordinary cause for hatred.

PROP. XLII. He who has conferred a benefit on anyone from motives of love or honour will feel pain, if he sees that the benefit is received without gratitude.

 Proof.—When a man loves something similar to himself, he endeavours, as far as he can, to bring it about that he should be loved thereby in return (III. xxxiii.). Therefore he who has conferred a benefit confers it in obedience to the desire, which he feels of being loved in return; that is (III. xxxiv.) from the hope of honour or (III. xxx. note) pleasure; hence he will endeavour, as far as he can, to conceive this cause of honour, or to regard it as actually existing. But, by the hypothesis, he conceives something else, which excludes the existence of the said cause of honour: wherefore he will thereat feel pain (III. xix.). Q.E.D.

PROP. XLIII. Hatred is increased by being reciprocated, and can on the other hand be destroyed by love.

 Proof.—He who conceives, that an object of his hatred hates him in return, will thereupon feel a new hatred, while the former hatred (by hypothesis) still remains (III. xl.). But if, on the other hand, he conceives that the object of hate loves him, he will to this extent (III. xxxviii.) regard himself with pleasure, and (III. xxix.) will endeavour to please the cause of his emotion. In other words, he will endeavour not to hate him (III. xli.), and not to affect him painfully; this endeavour (III. xxxvii.) will be greater or less in proportion to the emotion from which it arises. Therefore, if it be greater than that which arises from hatred, and through which the man endeavours to affect painfully the thing which he hates, it will get the better of it and banish the hatred from his mind. Q.E.D.

PROP. XLIV. Hatred which is completely vanquished by love passes into love: and love is thereupon greater than if hatred had not preceded it.

 Proof.—The proof proceeds in the same way as Prop. xxxviii. of this Part: for he who begins to love a thing, which he was wont to hate or regard with pain, from the very fact of loving feels pleasure. To this pleasure involved in love is added the pleasure arising from aid given to the endeavour to remove the pain involved in hatred (III. xxxvii.), accompanied by the idea of the former object of hatred as cause.

 Note.—Though this be so, no one will endeavour to hate anything, or to be affected with pain, for the sake of enjoying this greater pleasure; that is, no one will desire that he should be injured, in the hope of recovering from the injury, nor long to be ill for the sake of getting well. For everyone will always endeavour to persist in his being, and to ward off pain as far as he can. If the contrary is conceivable, namely, that a man should desire to hate someone, in order that he might love him the more thereafter, he will always desire to hate him. For the strength of love is in proportion to the strength of the hatred, wherefore the man would desire, that the hatred be continually increased more and more, and, for a similar reason, he would desire to become more and more ill, in order that he might take a greater pleasure in being restored to health: in such a case he would always endeavour to be ill, which (III. vi.) is absurd.

PROP. XLV. If a man conceives, that anyone similar to himself hates anything also similar to himself, which he loves, he will hate that person.

 Proof.—The beloved object feels reciprocal hatred towards him who hates it (III. xl.); therefore the lover, in conceiving that anyone hates the beloved object, conceives the beloved thing as affected by hatred, in other words (III. xiii.), by pain; consequently he is himself affected by pain accompanied by the idea of the hater of the beloved thing as cause; that is, he will hate him who hates anything which he himself loves (III. xiii. note). Q.E.D.

PROP. XLVI. If a man has been affected pleasurably or painfully by anyone, of a class or nation different from his own, and if the pleasure or pain has been accompanied by the idea of the said stranger as cause, under the general category of the class or nation: the man will feel love or hatred, not only to the individual stranger, but also to the whole class or nation whereto he belongs.

 Proof.—This is evident from III. xvi.

PROP. XLVII. Joy arising from the fact, that anything we hate is destroyed, or suffers other injury, is never unaccompanied by a certain pain in us.

 Proof.—This is evident from III. xxvii. For in so far as we conceive a thing similar to ourselves to be affected with pain, we ourselves feel pain.

 Note.—This proposition can also be proved from the Corollary to II. xvii. Whenever we remember anything, even if it does not actually exist, we regard it only as present, and the body is affected in the same manner; wherefore, in so far as the remembrance of the thing is strong, a man is determined to regard it with pain; this determination, while the image of the thing in question lasts, is indeed checked by the remembrance of other things excluding the existence of the aforesaid thing, but is not destroyed: hence, a man only feels pleasure in so far as the said determination is checked: for this reason the joy arising from the injury done to what we hate is repeated, every time we remember that object of hatred. For, as we have said, when the image of the thing in question, is aroused, inasmuch as it involves the thing's existence, it determines the man to regard the thing with the same pain as he was wont to do, when it actually did exist. However, since he has joined to the image of the thing other images, which exclude its existence, this determination to pain is forthwith checked, and the man rejoices afresh as often as the repetition takes place. This is the cause of men's pleasure in recalling past evils, and delight in narrating dangers from which they have escaped. For when men conceive a danger, they conceive it as still future, and are determined to fear it; this determination is checked afresh by the idea of freedom, which became associated with the idea of the danger when they escaped therefrom: this renders them secure afresh: therefore they rejoice afresh.

PROP. XLVIII. Love or hatred towards, for instance, Peter is destroyed, if the pleasure involved in the former, or the pain involved in the latter emotion, be associated with the idea of another cause: and will be diminished in proportion as we conceive Peter not to have been the sole cause of either emotion.

 Proof.—This Prop. is evident from the mere definition of love and hatred (III. xiii. note). For pleasure is called love towards Peter, and pain is called hatred towards Peter, simply in so far as Peter is regarded as the cause of one emotion or the other. When this condition of causality is either wholly or partly removed, the emotion towards Peter also wholly or in part vanishes. Q.E.D.

PROP. XLIX. Love or hatred towards a thing, which we conceive to be free, must, other conditions being similar, be greater than if it were felt towards a thing acting by necessity.

 Proof.—A thing which we conceive as free must (I. Def. vii.)be perceived through itself without anything else. If, therefore, we conceive it as the cause of pleasure or pain, we shall therefore (III. xiii. note) love it or hate it, and shall do so with the utmost love or hatred that can arise from the given emotion. But if the thing which causes the emotion be conceived as acting by necessity, we shall then (by the same Def. vii. Part I.) conceive it not as the sole cause, but as one of the causes of the emotion, and therefore our love or hatred towards it will be less. Q.E.D.

 Note.—Hence it follows, that men, thinking themselves to be free, feel more love or hatred towards one another than towards anything else: to this consideration we must add the imitation of emotions treated of in III. xxvii., xxxiv., xl. and xliii.

PROP. L. Anything whatever can be, accidentally, a cause of hope or fear.

 Proof.—This proposition is proved in the same way as III. xv., which see, together with the note to III. xviii.

 Note.—Things which are accidentally the causes of hope or fear are called good or evil omens. Now, in so far as such omens are the cause of hope or fear, they are (by the definitions of hope and fear given in III. xviii. note) the causes also of pleasure and pain; consequently we, to this extent, regard them with love or hatred, and endeavour either to invoke them as means towards that which we hope for, or to remove them as obstacles, or causes of that which we fear. It follows, further, from III. xxv., that we are naturally so constituted as to believe readily in that which we hope for, and with difficulty in that which we fear; moreover, we are apt to estimate such objects above or below their true value. Hence there have arisen superstitions, whereby men are everywhere assailed. However, I do not think it worth while to point out here the vacillations springing from hope and fear; it follows from the definition of these emotions, that there can be no hope without fear, and no fear without hope, as I will duly explain in the proper place. Further, in so far as we hope for or fear anything, we regard it with love or hatred; thus everyone can apply by himself to hope and fear what we have said concerning love and hatred.

PROP. LI. Different men may be differently affected by the same object, and the same man may be differently affected at different times by the same object.

 Proof.—The human body is affected by external bodies in a variety of ways (II. Post. iii.). Two men may therefore be differently affected at the same time, and therefore (by Ax. i. after Lemma iii. after II. xiii.) may be differently affected by one and the same object. Further (by the same Post.) the human body can be affected sometimes in one way, sometimes in another; consequently (by the same Axiom) it may be differently affected at different times by one and the same object. Q.E.D.

 Note.—We thus see that it is possible, that what one man loves another may hate, and that what one man fears another may not fear; or, again, that one and the same man may love what he once hated, or may be bold where he once was timid, and so on. Again, as everyone judges according to his emotions what is good, what bad, what better, and what worse (III. xxxix. note), it follows that men's judgments may vary no less than their emotions 10, hence when we compare some with others, we distinguish them solely by the diversity of their emotions, and style some intrepid, others timid, others by some other epithet. For instance, I shall call a man intrepid, if he despises an evil which I am accustomed to fear; if I further take into consideration, that, in his desire to injure his enemies and to benefit those whom he loves, he is not restrained by the fear of an evil which is sufficient to restrain me, I shall call him daring. Again, a man will appear timid to me, if he fears an evil which I am accustomed to despise; and if I further take into consideration that his desire is restrained by the fear of an evil, which is not sufficient to restrain me, I shall say that he is cowardly; and in like manner will everyone pass judgment.

 Lastly, from this inconstancy in the nature of human judgment, inasmuch as a man often judges things solely by his emotions, and inasmuch as the things which he believes cause pleasure or pain, and therefore endeavours to promote or prevent, are often purely imaginary, not to speak of the uncertainty of things alluded to in III. xxviii.; we may readily conceive that a man may be at one time affected with pleasure, and at another with pain, accompanied by the idea of himself as cause. Thus we can easily understand what are Repentance and Self-complacency. Repentance is pain, accompanied by the idea of one's self as cause; Self-complacency is pleasure, accompanied by the idea of one's self as cause, and these emotions are most intense because men believe themselves to be free (III. xlix.).

PROP. LII. An object which we have formerly seen in conjunction with others, and which we do not conceive to have any property that is not common to many, will not be regarded by us for so long, as an object which we conceive to have some property peculiar to itself.

 Proof.—As soon as we conceive an object which we have seen in conjunction with others, we at once remember those others (II. xviii. and note), and thus we pass forthwith from the contemplation of one object to the contemplation of another object. And this is the case with the object, which we conceive to have no property that is not common to many. For we thereupon assume that we are regarding therein nothing, which we have not before seen in conjunction with other objects. But when we suppose that we conceive an object something special, which we have never seen before, we must needs say that the mind, while regarding that object, has in itself nothing which it can fall to regarding instead thereof; therefore it is determined to the contemplation of that object only. Therefore an object, &c. Q.E.D.

 Note.—This mental modification, or imagination of a particular thing, in so far as it is alone in the mind, is called Wonder; but if it be excited by an object of fear, it is called Consternation, because wonder at an evil keeps a man so engrossed in the simple contemplation thereof, that he has no power to think of anything else whereby he might avoid the evil. If, however, the object of wonder be a man's prudence, industry, or anything of that sort, inasmuch as the said man, is thereby regarded as far surpassing ourselves, wonder is called Veneration; otherwise, if a man's anger, envy, &c., be what we wonder at, the emotion is called Horror. Again, if it be the prudence, industry, or what not, of a man we love, that we wonder at, our love will on this account be the greater (III. xii.), and when joined to wonder or veneration is called Devotion. We may in like manner conceive hatred, hope, confidence, and the other emotions, as associated with wonder; and we should thus be able to deduce more emotions than those which have obtained names in ordinary speech. Whence it is evident, that the names of the emotions have been applied in accordance rather with their ordinary manifestations than with an accurate knowledge of their nature.

 To wonder is opposed Contempt, which generally arises from the fact that, because we see someone wondering at, loving, or fearing something, or because something, at first sight, appears to be like things, which we ourselves wonder at, love, fear, &c., we are, in consequence (III. xv. Coroll. and III. xxvii.), determined to wonder at, love, or fear that thing. But if from the presence, or more accurate contemplation of the said thing, we are compelled to deny concerning it all that can be the cause of wonder, love, fear, &c., the mind then, by the presence of the thing, remains determined to think rather of those qualities which are not in it, than of those which are in it; whereas, on the other hand, the presence of the object would cause it more particularly to regard that which is therein. As devotion springs from wonder at a thing which we love, so does Derision spring from contempt of a thing which we hate or fear, and Scorn from contempt of folly, as veneration from wonder at prudence. Lastly, we can conceive the emotions of love, hope, honour, &c., in association with contempt, and can thence deduce other emotions, which are not distinguished one from another by any recognized name.

PROP. LIII. When the mind regards itself and its own power of activity, it feels pleasure: and that pleasure is greater in proportion to the distinctness wherewith it conceives itself and its own power of activity.

 Proof.—A man does not know himself except through the modifications of his body, and the ideas thereof (II. xix. and xxiii.). When, therefore, the mind is able to contemplate itself, it is thereby assumed to pass to a greater perfection, or (III. xi. note) to feel pleasure; and the pleasure will be greater in proportion to the distinctness, wherewith it is able to conceive itself and its own power of activity. Q.E.D.

 Corollary.—This pleasure is fostered more and more, in proportion as a man conceives himself to be praised by others. For the more he conceives himself as praised by others, the more he will imagine them to be affected with pleasure, accompanied by the idea of himself (III. xxix. note); thus he is (III. xxvii.) himself affected with greater pleasure, accompanied by the idea of himself. Q.E.D.

PROP. LIV. The mind endeavours to conceive only such things as assert its power of activity.

 Proof.—The endeavour or power of the mind is the actual essence thereof (III. vii.); but the essence of the mind obviously only affirms that which the mind is and can do; not that which it neither is nor can do; therefore the mind endeavours to conceive only such things as assert or affirm its power of activity. Q.E.D.

PROP. LV. When the mind contemplates its own weakness, it feels pain thereat.

 Proof.—The essence of the mind only affirms that which the mind is, or can do; in other words, it is the mind's nature to conceive only such things as assert its power of activity (last Prop.). Thus, when we say that the mind contemplates its own weakness, we are merely saying that while the mind is attempting to conceive something which asserts its power of activity, it is checked in its endeavour—in other words (III. xi. note), it feels pain. Q.E.D.

 Corollary.—This pain is more and more fostered, if a man conceives that he is blamed by others; this may be proved in the same way as the corollary to III. liii.

 Note.—This pain, accompanied by the idea of our own weakness, is called humility; the pleasure, which springs from the contemplation of ourselves, is called self-love or self-complacency. And inasmuch as this feeling is renewed as often as a man contemplates his own virtues, or his own power of activity, it follows that everyone is fond of narrating his own exploits, and displaying the force both of his body and mind, and also that, for this reason, men are troublesome to one another. Again, it follows that men are naturally envious (III. xxiv. note, and III. xxxii. note), rejoicing in the shortcomings of their equals, and feeling pain at their virtues. For whenever a man conceives his own actions, he is affected with pleasure (III. liii.), in proportion as his actions display more perfection, and he conceives them more distinctly-that is (II. xl. note), in proportion as he can distinguish them from others, and regard them as something special. Therefore, a man will take most pleasure in contemplating himself, when he contemplates some quality which he denies to others. But, if that which he affirms of himself be attributable to the idea of man or animals in general, he will not be so greatly pleased: he will, on the contrary, feel pain, if he conceives that his own actions fall short when compared with those of others. This pain (III. xxviii.) he will endeavour to remove, by putting a wrong construction on the actions of his equals, or by, as far as he can, embellishing his own.

 It is thus apparent that men are naturally prone to hatred and envy, which latter is fostered by their education. For parents are accustomed to incite their children to virtue solely by the spur of honour and envy. But, perhaps, some will scruple to assent to what I have said, because we not seldom admire men's virtues, and venerate their possessors. In order to remove such doubts, I append the following corollary.

 Corollary.—No one envies the virtue of anyone who is not his equal.

 Proof.—Envy is a species of hatred (III. xxiv. note) or (III. xiii. note) pain, that is (III. xi. note), a modification whereby a man's power of activity, or endeavour towards activity, is checked. But a man does not endeavour or desire to do anything, which cannot follow from his nature as it is given; therefore a man will not desire any power of activity or virtue (which is the same thing) to be attributed to him, that is appropriate to another's nature and foreign to his own; hence his desire cannot be checked, nor he himself pained by the contemplation of virtue in some one unlike himself, consequently he cannot envy such an one. But he can envy his equal, who is assumed to have the same nature as himself. Q.E.D.

 Note.—When, therefore, as we said in the note to III. lii., we venerate a man, through wonder at his prudence, fortitude, &c., we do so, because we conceive those qualities to be peculiar to him, and not as common to our nature; we, therefore, no more envy their possessor, than we envy trees for being tall, or lions for being courageous.

PROP. LVI. There are as many kinds of pleasure, of pain, of desire, and of every emotion compounded of these, such as vacillations of spirit, or derived from these, such as love, hatred, hope, fear, &c., as there are kinds of objects whereby we are affected.

 Proof.—Pleasure and pain, and consequently the emotions compounded thereof, or derived therefrom, are passions, or passive states (III. xi. note); now we are necessarily passive (III. i.), in so far as we have inadequate ideas; and only in so far as we have such ideas are we passive (III. iii.); that is, we are only necessarily passive (II. xl. note), in so far as we conceive, or (II. xvii. and note) in so far as we are affected by an emotion, which involves the nature of our own body, and the nature of an external body. Wherefore the nature of every passive state must necessarily be so explained, that the nature of the object whereby we are affected be expressed. Namely, the pleasure, which arises from, say, the object A, involves the nature of that object A, and the pleasure, which arises from the object B, involves the nature of the object B; wherefore these two pleasurable emotions are by nature different, inasmuch as the causes whence they arise are by nature different. So again the emotion of pain, which arises from one object, is by nature different from the pain arising from another object, and, similarly, in the case of love, hatred, hope, fear, vacillation, &c.

 Thus, there are necessarily as many kinds of pleasure, pain, love, hatred, &c., as there are kinds of objects whereby we are affected. Now desire is each man's essence or nature, in so far as it is conceived as determined to a particular action by any given modification of itself (III. ix. note); therefore, according as a man is affected through external causes by this or that kind of pleasure, pain, love, hatred, &c., in other words, according as his nature is disposed in this or that manner, so will his desire be of one kind or another, and the nature of one desire must necessarily differ from the nature of another desire, as widely as the emotions differ, wherefrom each desire arose. Thus there are as many kinds of desire, as there are kinds of pleasure, pain, love, &c., consequently (by what has been shown) there are as many kinds of desire, as there are kinds of objects whereby we are affected. Q.E.D.

 Note.—Among the kinds of emotions, which, by the last proposition, must be very numerous, the chief are luxury, drunkenness, lust, avarice, and ambition, being merely species of love or desire, displaying the nature of those emotions in a manner varying according to the object, with which they are concerned. For by luxury, drunkenness, lust, avarice, ambition, &c., we simply mean the immoderate love of feasting, drinking, venery, riches, and fame. Furthermore, these emotions, in so far as we distinguish them from others merely by the objects wherewith they are concerned, have no contraries. For temperance, sobriety, and chastity, which we are wont to oppose to luxury, drunkenness, and lust, are not emotions or passive states, but indicate a power of the mind which moderates the last-named emotions. However, I cannot here explain the remaining kinds of emotions (seeing that they are as numerous as the kinds of objects), nor, if I could, would it be necessary. It is sufficient for our purpose, namely, to determine the strength of the emotions, and the mind's power over them, to have a general definition of each emotion. It is sufficient, I repeat, to understand the general properties of the emotions and the mind, to enable us to determine the quality and extent of the mind's power in moderating and checking the emotions. Thus, though there is a great difference between various emotions of love, hatred, or desire, for instance between love felt towards children, and love felt towards a wife, there is no need for us to take cognizance of such differences, or to track out further the nature and origin of the emotions.

PROP. LVII. Any emotion of a given individual differs from the emotion of another individual, only in so far as the essence of the one individual differs from the essence of the other.

 Proof.—This proposition is evident from Ax. i. (which see after Lemma iii. Prop. xiii., Part II.). Nevertheless, we will prove it from the nature of the three primary emotions.

 All emotions are attributable to desire, pleasure, or pain, as their definitions above given show. But desire is each man's nature or essence (III. ix. note); therefore desire in one individual differs from desire in another individual, only in so far as the nature or essence of the one differs from the nature or essence of the other. Again, pleasure and pain are passive states or passions, whereby every man's power or endeavour to persist in his being is increased or diminished, helped or hindered (III. xi. and note). But by the endeavour to persist in its being, in so far as it is attributable to mind and body in conjunction, we mean appetite and desire (III. ix. note); therefore pleasure and pain are identical with desire or appetite, in so far as by external causes they are increased or diminished, helped or hindered, in other words, they are every man's nature; wherefore the pleasure and pain felt by one man differ from the pleasure and pain felt by another man, only in so far as the nature or essence of the one man differs from the essence of the other; consequently, any emotion of one individual only differs, &c. Q.E.D.

 Note.—Hence it follows, that the emotions of the animals which are called irrational (for after learning the origin of mind we cannot doubt that brutes feel) only differ from man's emotions, to the extent that brute nature differs from human nature. Horse and man are alike carried away by the desire of procreation; but the desire of the former is equine, the desire of the latter is human. So also the lusts and appetites of insects, fishes, and birds must needs vary according to the several natures. Thus, although each individual lives content and rejoices in that nature belonging to him wherein he has his being, yet the life, wherein each is content and rejoices, is nothing else but the idea, or soul, of the said individual, and hence the joy of one only differs in nature from the joy of another, to the extent that the essence of one differs from the essence of another. Lastly, it follows from the foregoing proposition, that there is no small difference between the joy which actuates, say, a drunkard, and the joy possessed by a philosopher, as I just mention here by the way. Thus far I have treated of the emotions attributable to man, in so far as he is passive. It remains to add a few words on those attributable to him in so far as he is active.

PROP. LVIII. Besides pleasure and desire, which are passivities or passions, there are other emotions derived from pleasure and desire, which are attributable to us in so far as we are active.

 Proof.—When the mind conceives itself and its power of activity, it feels pleasure (III. liii.): now the mind necessarily contemplates itself, when it conceives a true or adequate idea (II. xliii.). But the mind does conceive certain adequate ideas (II. xl. note 2.). Therefore it feels pleasure in so far as it conceives adequate ideas; that is, in so far as it is active (III. i.). Again, the mind, both in so far as it has clear and distinct ideas, and in so far as it has confused ideas, endeavours to persist in its own being (III. ix.); but by such an endeavour we mean desire (by the note to the same Prop.); therefore, desire is also attributable to us, in so far as we understand, or (III. i.) in so far as we are active. Q.E.D.

PROP. LIX. Among all the emotions attributable to the mind as active, there are none which cannot be referred to pleasure or desire.

 Proof.—All emotions can be referred to desire, pleasure, or pain, as their definitions, already given, show. Now by pain we mean that the mind's power of thinking is diminished or checked (III. xi. and note); therefore, in so far as the mind feels pain, its power of understanding, that is, of activity, is diminished or checked (III. i.); therefore, no painful emotions can be attributed to the mind in virtue of its being active, but only emotions of pleasure and desire, which (by the last Prop.) are attributable to the mind in that condition. Q.E.D.

 Note.—All actions following from emotion, which are attributable to the mind in virtue of its understanding, I set down to strength of character (fortitudo), which I divide into courage (animositas) and highmindedness (generositas). By courage I mean the desire whereby every man strives to preserve his own being in accordance solely with the dictates of reason. By highmindedness I mean the desire whereby every man endeavours, solely under the dictates of reason, to aid other men and to unite them to himself in friendship. Those actions, therefore, which have regard solely to the good of the agent I set down to courage, those which aim at the good of others I set down to highmindedness. Thus temperance, sobriety, and presence of mind in danger, &c., are varieties of courage; courtesy, mercy, &c., are varieties of highmindedness.

 I think I have thus explained, and displayed through their primary causes the principal emotions and vacillations of spirit, which arise from the combination of the three primary emotions, to wit, desire, pleasure, and pain. It is evident from what I have said, that we are in many ways driven about by external causes, and that like waves of the sea driven by contrary winds we toss to and fro unwitting of the issue and of our fate. But I have said, that I have only set forth the chief conflicting emotions, not all that might be given. For, by proceeding in the same way as above, we can easily show that love is united to repentance, scorn, shame, &c. I think everyone will agree from what has been said, that the emotions may be compounded one with another in so many ways, and so many variations may arise therefrom, as to exceed all possibility of computation. However, for my purpose, it is enough to have enumerated the most important; to reckon up the rest which I have omitted would be more curious than profitable. It remains to remark concerning love, that it very often happens that while we are enjoying a thing which we longed for, the body, from the act of enjoyment, acquires a new disposition, whereby it is determined in another way, other images of things are aroused in it, and the mind begins to conceive and desire something fresh. For example, when we conceive something which generally delights us with its flavour, we desire to enjoy, that is, to eat it. But whilst we are thus enjoying it, the stomach is filled and the body is otherwise disposed. If, therefore, when the body is thus otherwise disposed, the image of the food which is present be stimulated, and consequently the endeavour or desire to eat it be stimulated also, the new disposition of the body will feel repugnance to the desire or attempt, and consequently the presence of the food which we formerly longed for will become odious. This revulsion of feeling is called satiety or weariness. For the rest, I have neglected the outward modifications of the body observable in emotions, such, for instance, as trembling, pallor, sobbing, laughter, &c., for these are attributable to the body only, without any reference to the mind. Lastly, the definitions of the emotions require to be supplemented in a few points; I will therefore repeat them, interpolating such observations as I think should here and there be added.

DEFINITIONS OF THE EMOTIONS

I. Desire is the actual essence of man, in so far as it is conceived, as determined to a particular activity by some given modification of itself.

 Explanation.—We have said above, in the note to Prop. ix. of this part, that desire is appetite, with consciousness thereof; further, that appetite is the essence of man, in so far as it is determined to act in a way tending to promote its own persistence. But, in the same note, I also remarked that, strictly speaking, I recognize no distinction between appetite and desire. For whether a man be conscious of his appetite or not, it remains one and the same appetite. Thus, in order to avoid the appearance of tautology, I have refrained from explaining desire by appetite; but I have take care to define it in such a manner, as to comprehend, under one head, all those endeavours of human nature, which we distinguish by the terms appetite, will, desire, or impulse. I might, indeed, have said, that desire is the essence of man, in so far as it is conceived as determined to a particular activity; but from such a definition (cf. II. xxiii.) it would not follow that the mind can be conscious of its desire or appetite. Therefore, in order to imply the cause of such consciousness, it was necessary to add, in so far as it is determined by some given modification, &c. For, by a modification of man's essence, we understand every disposition of the said essence, whether such disposition be innate, or whether it be conceived solely under the attribute of thought, or solely under the attribute of extension, or whether, lastly, it be referred simultaneously to both these attributes. By the term desire, then, I here mean all man's endeavours, impulses, appetites, and volitions, which vary according to each man's disposition, and are, therefore, not seldom opposed one to another, according as a man is drawn in different directions, and knows not where to turn.

II. Pleasure is the transition of a man from a less to a greater perfection.

III. Pain is the transition of a man from a greater to a less perfection.

 Explanation—I say transition: for pleasure is not perfection itself. For, if man were born with the perfection to which he passes, he would possess the same, without the emotion of pleasure. This appears more clearly from the consideration of the contrary emotion, pain. No one can deny, that pain consists in the transition to a less perfection, and not in the less perfection itself: for a man cannot be pained, in so far as he partakes of perfection of any degree. Neither can we say, that pain consists in the absence of a greater perfection. For absence is nothing, whereas the emotion of pain is an activity; wherefore this activity can only be the activity of transition from a greater to a less perfection-in other words, it is an activity whereby a man's power of action is lessened or constrained (cf. III. xi. note). I pass over the definitions of merriment, stimulation, melancholy, and grief, because these terms are generally used in reference to the body, and are merely kinds of pleasure or pain.

IV. Wonder is the conception (imaginatio) of anything, wherein the mind comes to a stand, because the particular concept in question has no connection with other concepts (cf. III. lii. and note).

 Explanation—In the note to II. xviii. we showed the reason, why the mind, from the contemplation of one thing, straightway falls to the contemplation of another thing, namely, because the images of the two things are so associated and arranged, that one follows the other. This state of association is impossible, if the image of the thing be new; the mind will then be at a stand in the contemplation thereof, until it is determined by other causes to think of something else.

 Thus the conception of a new object, considered in itself, is of the same nature as other conceptions; hence, I do not include wonder among the emotions, nor do I see why I should so include it, inasmuch as this distraction of the mind arises from no positive cause drawing away the mind from other objects, but merely from the absence of a cause, which should determine the mind to pass from the contemplation of one object to the contemplation of another.

 I, therefore, recognize only three primitive or primary emotions (as I said in the note to III. xi.), namely, pleasure, pain, and desire. I have spoken of wonder simply because it is customary to speak of certain emotions springing from the three primitive ones by different names, when they are referred to the objects of our wonder. I am led by the same motive to add a definition of contempt.

V. Contempt is the conception of anything which touches the mind so little, that its presence leads the mind to imagine those qualities which are not in it rather than such as are in it (cf. III. lii. note).

 The definitions of veneration and scorn I here pass over, for I am not aware that any emotions are named after them.

VI. Love is pleasure, accompanied by the idea of an external cause.

 Explanation—This definition explains sufficiently clearly the essence of love; the definition given by those authors who say that love is the lover's wish to unite himself to the loved object expresses a property, but not the essence of love; and, as such authors have not sufficiently discerned love's essence, they have been unable to acquire a true conception of its properties, accordingly their definition is on all hands admitted to be very obscure. It must, however, be noted, that when I say that it is a property of love, that the lover should wish to unite himself to the beloved object, I do not here mean by wish consent, or conclusion, or a free decision of the mind (for I have shown such, in II. xlviii., to be fictitious); neither do I mean a desire of being united to the loved object when it is absent, or of continuing in its presence when it is at hand; for love can be conceived without either of these desires; but by wish I mean the contentment, which is in the lover, on account of the presence of the beloved object, whereby the pleasure of the lover is strengthened, or at least maintained.

VII. Hatred is pain, accompanied by the idea of an external cause.

 Explanation—These observations are easily grasped after what has been said in the explanation of the preceding definition (cf. also III. xiii. note).

VIII. Inclination is pleasure, accompanied by the idea of something which is accidentally a cause of pleasure.

IX. Aversion is pain, accompanied by the idea of something which is accidentally the cause of pain (cf. III. xv. note).

X. Devotion is love towards one whom we admire.

 Explanation—Wonder (admiratio) arises (as we have shown, III. lii.) from the novelty of a thing. If, therefore, it happens that the object of our wonder is often conceived by us, we shall cease to wonder at it; thus we see, that the emotion of devotion readily degenerates into simple love.

XI. Derision is pleasure arising from our conceiving the presence of a quality, which we despise, in an object which we hate.

 Explanation—In so far as we despise a thing which we hate, we deny existence thereof (III. lii. note), and to that extent rejoice (III. xx.). But since we assume that man hates that which he derides, it follows that the pleasure in question is not without alloy (cf. III. xlvii. note).

XII. Hope is an inconstant pleasure, arising from the idea of something past or future, whereof we to a certain extent doubt the issue.

XIII. Fear is an inconstant pain arising from the idea of something past or future, whereof we to a certain extent doubt the issue (cf. III. xviii. note).

 Explanation—From these definitions it follows, that there is no hope unmingled with fear, and no fear unmingled with hope. For he, who depends on hope and doubts concerning the issue of anything, is assumed to conceive something, which excludes the existence of the said thing in the future; therefore he, to this extent, feels pain (cf. III. xix.); consequently, while dependent on hope, he fears for the issue. Contrariwise he, who fears, in other words doubts, concerning the issue of something which he hates, also conceives something which excludes the existence of the thing in question; to this extent he feels pleasure, and consequently to this extent he hopes that it will turn out as he desires (III. xx.).

XIV. Confidence is pleasure arising from the idea of something past or future, wherefrom all cause of doubt has been removed.

XV. Despair is pain arising from the idea of something past or future, wherefrom all cause of doubt has been removed.

 Explanation—Thus confidence springs from hope, and despair from fear, when all cause for doubt as to the issue of an event has been removed: this comes to pass, because man conceives something past or future as present and regards it as such, or else because he conceives other things, which exclude the existence of the causes of his doubt. For, although we can never be absolutely certain of the issue of any particular event (II. xxxi. Coroll.), it may nevertheless happen that we feel no doubt concerning it. For we have shown, that to feel no doubt concerning a thing is not the same as to be quite certain of it (II. xlix. note). Thus it may happen that we are affected by the same emotion of pleasure or pain concerning a thing past or future, as concerning the conception of a thing present; this I have already shown in III. xviii., to which, with its note, I refer the reader.

XVI. Joy is pleasure accompanied by the idea of something past, which has had an issue beyond our hope.

XVII. Disappointment is pain accompanied by the idea of something past, which has had an issue contrary to our hope.

XVIII. Pity is pain accompanied by the idea of evil, which has befallen someone else whom we conceive to be like ourselves (cf. III. xxii. note, and III. xxvii. note).

 Explanation—Between pity and sympathy (misericordia) there seems to be no difference, unless perhaps that the former term is used in reference to a particular action, and the latter in reference to a disposition.

XIX. Approval is love towards one who has done good to another.

XX. Indignation is hatred towards one who has done evil to another.

 Explanation—I am aware that these terms are employed in senses somewhat different from those usually assigned. But my purpose is to explain, not the meaning of words, but the nature of things. I therefore make use of such terms, as may convey my meaning without any violent departure from their ordinary signification. One statement of my method will suffice. As for the cause of the above-named emotions see III. xxvii. Coroll. i., and III. xxii. note.

XXI. Partiality is thinking too highly of anyone because of the love we bear him.

XXII. Disparagement is thinking too meanly of anyone because we hate him.

 Explanation—Thus partiality is an effect of love, and disparagement an effect of hatred: so that partiality may also be defined as love, in so far as it induces a man to think too highly of a beloved object. Contrariwise, disparagement may be defined as hatred, in so far as it induces a man to think too meanly of a hated object. Cf. III. xxvi. note.

XXIII. Envy is hatred, in so far as it induces a man to be pained by another's good fortune, and to rejoice in another's evil fortune.

 Explanation—Envy is generally opposed to sympathy, which, by doing some violence to the meaning of the word, may therefore be thus defined:

XXIV. Sympathy (misericordia) is love, in so far as it induces a man to feel pleasure at another's good fortune, and pain at another's evil fortune.

 Explanation—Concerning envy see the notes to III. xxiv. and xxxii. These emotions also arise from pleasure or pain accompanied by the idea of something external, as cause either in itself or accidentally. I now pass on to other emotions, which are accompanied by the idea of something within as a cause.

XXV. Self-approval is pleasure arising from a man's contemplation of himself and his own power of action.

XXVI. Humility is pain arising from a man's contemplation of his own weakness of body or mind.

 Explanation—Self-complacency is opposed to humility, in so far as we thereby mean pleasure arising from a contemplation of our own power of action; but, in so far as we mean thereby pleasure accompanied by the idea of any action which we believe we have performed by the free decision of our mind, it is opposed to repentance, which we may thus define:

XXVII. Repentance is pain accompanied by the idea of some action, which we believe we have performed by the free decision of our mind.

 Explanation—The causes of these emotions we have set forth in III. li. note, and in III. liii., liv., lv. and note. Concerning the free decision of the mind see II. xxxv. note. This is perhaps the place to call attention to the fact, that it is nothing wonderful that all those actions, which are commonly called wrong, are followed by pain, and all those, which are called right, are followed by pleasure. We can easily gather from what has been said, that this depends in great measure on education. Parents, by reprobating the former class of actions, and by frequently chiding their children because of them, and also by persuading to and praising the latter class, have brought it about, that the former should be associated with pain and the latter with pleasure. This is confirmed by experience. For custom and religion are not the same among all men, but that which some consider sacred others consider profane, and what some consider honourable others consider disgraceful. According as each man has been educated, he feels repentance for a given action or glories therein.

XXVIII. Pride is thinking too highly of one's self from self-love.

 Explanation—Thus pride is different from partiality, for the latter term is used in reference to an external object, but pride is used of a man thinking too highly of himself. However, as partiality is the effect of love, so is pride the effect or property of self-love, which may therefore be thus defined, love of self or self-approval, in so far as it leads a man to think too highly of himself. To this emotion there is no contrary. For no one thinks too meanly of himself because of self-hatred; I say that no one thinks too meanly of himself, in so far as he conceives that he is incapable of doing this or that. For whatsoever a man imagines that he is incapable of doing, he imagines this of necessity, and by that notion he is so disposed, that he really cannot do that which he conceives that he cannot do. For, so long as he conceives that he cannot do it, so long is he not determined to do it, and consequently so long is it impossible for him to do it. However, if we consider such matters as only depend on opinion, we shall find it conceivable that a man may think too meanly of himself; for it may happen, that a man, sorrowfully regarding his own weakness, should imagine that he is despised by all men, while the rest of the world are thinking of nothing less than of despising him. Again, a man may think too meanly of himself, if he deny of himself in the present something in relation to a future time of which he is uncertain. As, for instance, if he should say that he is unable to form any clear conceptions, or that he can desire and do nothing but what is wicked and base, &c. We may also say, that a man thinks too meanly of himself, when we see him from excessive fear of shame refusing to do things which others, his equals, venture. We can, therefore, set down as a contrary to pride an emotion which I will call self-abasement, for as from self-complacency springs pride, so from humility springs self-abasement, which I will accordingly thus define:

XXIX. Self-abasement is thinking too meanly of one's self by reason of pain.

 Explanation—We are nevertheless generally accustomed to oppose pride to humility, but in that case we pay more attention to the effect of either emotion than to its nature. We are wont to call proud the man who boasts too much (III. xxx. note), who talks of nothing but his own virtues and other people's faults, who wishes to be first; and lastly who goes through life with a style and pomp suitable to those far above him in station. On the other hand, we call humble the man who too often blushes, who confesses his faults, who sets forth other men's virtues, and who, lastly, walks with bent head and is negligent of his attire. However, these emotions, humility and self-abasement, are extremely rare. For human nature, considered in itself, strives against them as much as it can (see III. xiii., liv.); hence those, who are believed to be most self-abased and humble, are generally in reality the most ambitious and envious.

XXX. Honour11 is pleasure accompanied by the idea of some action of our own, which we believe to be praised by others.

XXXI. Shame is pain accompanied by the idea of some action of our own, which we believe to be blamed by others.

 Explanation—On this subject see the note to III. xxx. But we should here remark the difference which exists between shame and modesty. Shame is the pain following the deed whereof we are ashamed. Modesty is the fear or dread of shame, which restrains a man from committing a base action. Modesty is usually opposed to shamelessness, but the latter is not an emotion, as I will duly show; however, the names of the emotions (as I have remarked already) have regard rather to their exercise than to their nature.

 I have now fulfilled the task of explaining the emotions arising from pleasure and pain. I therefore proceed to treat of those which I refer to desire.

XXXII. Regret is the desire or appetite to possess something, kept alive by the remembrance of the said thing, and at the same time constrained by the remembrance of other things which exclude the existence of it.

 Explanation—When we remember a thing, we are by that very fact, as I have already said more than once, disposed to contemplate it with the same emotion as if it were something present; but this disposition or endeavour, while we are awake, is generally checked by the images of things which exclude the existence of that which we remember. Thus when we remember something which affected us with a certain pleasure, we by that very fact endeavour to regard it with the same emotion of pleasure as though it were present, but this endeavour is at once checked by the remembrance of things which exclude the existence of the thing in question. Wherefore regret is, strictly speaking, a pain opposed to that of pleasure, which arises from the absence of something we hate (cf. III. xlvii. note). But, as the name regret seems to refer to desire, I set this emotion down, among the emotions springing from desire.

XXXIII. Emulation is the desire of something, engendered in us by our conception that others have the same desire.

 Explanation—He who runs away, because he sees others running away, or he who fears, because he sees others in fear; or again, he who, on seeing that another man has burnt his hand, draws towards him his own hand, and moves his body as though his own were burnt; such an one can be said to imitate another's emotion, but not to emulate him; not because the causes of emulation and imitation are different, but because it has become customary to speak of emulation only in him, who imitates that which we deem to be honourable, useful, or pleasant. As to the cause of emulation, cf. III. xxvii. and note. The reason why this emotion is generally coupled with envy may be seen from III. xxxii. and note.

XXXIV. Thankfulness or Gratitude is the desire or zeal springing from love, whereby we endeavour to benefit him, who with similar feelings of love has conferred a benefit on us. Cf. III. xxxix. note and xl.

XXXV. Benevolence is the desire of benefiting one whom we pity. Cf. III. xxvii. note.

XXXVI. Anger is the desire, whereby through hatred we are induced to injure one whom we hate, III. xxxix.

XXXVII. Revenge is the desire whereby we are induced, through mutual hatred, to injure one who, with similar feelings, has injured us. (See III. xl. Coroll. ii and note.)

XXXVIII. Cruelty or savageness is the desire, whereby a man is impelled to injure one whom we love or pity.

 Explanation—To cruelty is opposed clemency, which is not a passive state of the mind, but a power whereby man restrains his anger and revenge.

XXXIX. Timidity is the desire to avoid a greater evil, which we dread, by undergoing a lesser evil. Cf. III. xxxix. note.

XL. Daring is the desire, whereby a man is set on to do something dangerous which his equals fear to attempt.

XLI. Cowardice is attributed to one, whose desire is checked by the fear of some danger which his equals dare to encounter.

 Explanation—Cowardice is, therefore, nothing else but the fear of some evil, which most men are wont not to fear; hence I do not reckon it among the emotions springing from desire. Nevertheless, I have chosen to explain it here, because, in so far as we look to the desire, it is truly opposed to the emotion of daring.

XLII. Consternation is attributed to one, whose desire of avoiding evil is checked by amazement at the evil which he fears.

 Explanation—Consternation is, therefore, a species of cowardice. But, inasmuch as consternation arises from a double fear, it may be more conveniently defined as a fear which keeps a man so bewildered and wavering, that he is not able to remove the evil. I say bewildered, in so far as we understand his desire of removing the evil to be constrained by his amazement. I say wavering, in so far as we understand the said desire to be constrained by the fear of another evil, which equally torments him: whence it comes to pass that he knows not, which he may avert of the two. On this subject, see III. xxxix. note, and III. lii. note. Concerning cowardice and daring, see III. li. note.

XLIII. Courtesy, or deference (Humanitas seu modestia), is the desire of acting in a way that should please men, and refraining from that which should displease them.

XLIV. Ambition is the immoderate desire of power.

 Explanation—Ambition is the desire, whereby all the emotions(cf. III. xxvii. and xxxi.) are fostered and strengthened; therefore this emotion can with difficulty be overcome. For, so long as a man is bound by any desire, he is at the same time necessarily bound by this. "The best men," says Cicero, "are especially led by honour. Even philosophers, when they write a book contemning honour, sign their names thereto," and so on.

XLV. Luxury is excessive desire, or even love of living sumptuously.

XLVI. Intemperance is the excessive desire and love of drinking.

XLVII. Avarice is the excessive desire and love of riches.

XLVIII. Lust is desire and love in the matter of sexual intercourse.

 Explanation—Whether this desire be excessive or not, it is still called lust. These last five emotions (as I have shown in III. lvi.) have on contraries. For deference is a species of ambition. Cf. III. xxix. note.

 Again, I have already pointed out, that temperance, sobriety, and chastity indicate rather a power than a passivity of the mind. It may, nevertheless, happen, that an avaricious, an ambitious, or a timid man may abstain from excess in eating, drinking, or sexual indulgence, yet avarice, ambition, and fear are not contraries to luxury, drunkenness, and debauchery. For an avaricious man often is glad to gorge himself with food and drink at another man's expense. An ambitious man will restrain himself in nothing, so long as he thinks his indulgences are secret; and if he lives among drunkards and debauchees, he will, from the mere fact of being ambitious, be more prone to those vices. Lastly, a timid man does that which he would not. For though an avaricious man should, for the sake of avoiding death, cast his riches into the sea, he will none the less remain avaricious; so, also, if a lustful man is downcast, because he cannot follow his bent, he does not, on the ground of abstention, cease to be lustful. In fact, these emotions are not so much concerned with the actual feasting, drinking, &c., as with the appetite and love of such. Nothing, therefore, can be opposed to these emotions, but high-mindedness and valour, whereof I will speak presently.

 The definitions of jealousy and other waverings of the mind I pass over in silence, first, because they arise from the compounding of the emotions already described; secondly, because many of them have no distinctive names, which shows that it is sufficient for practical purposes to have merely a general knowledge of them. However, it is established from the definitions of the emotions, which we have set forth, that they all spring from desire, pleasure, or pain, or, rather, that there is nothing besides these three; wherefore each is wont to be called by a variety of names in accordance with its various relations and extrinsic tokens. If we now direct our attention to these primitive emotions, and to what has been said concerning the nature of the mind, we shall be able thus to define the emotions, in so far as they are referred to the mind only.

GENERAL DEFINITION OF THE EMOTIONS

Emotion, which is called a passivity of the soul, is a confused idea, whereby the mind affirms concerning its body, or any part thereof, a force for existence (existendi vis) greater or less than before, and by the presence of which the mind is determined to think of one thing rather than another.

 Explanation—I say, first, that emotion or passion of the soul is a confused idea. For we have shown that the mind is only passive, in so far as it has inadequate or confused ideas. (III. iii.) I say, further, whereby the mind affirms concerning its body or any part thereof a force for existence greater than before. For all the ideas of bodies, which we possess, denote rather the actual disposition of our own body (II. xvi. Coroll. ii.) than the nature of an external body. But the idea which constitutes the reality of an emotion must denote or express the disposition of the body, or of some part thereof, because its power of action or force for existence is increased or diminished, helped or hindered. But it must be noted that, when I say a greater or less force for existence than before, I do not mean that the mind compares the present with the past disposition of the body, but that the idea which constitutes the reality of an emotion affirms something of the body, which, in fact, involves more or less of reality than before.

 And inasmuch as the essence of mind consists in the fact (II. xi., xiii.), that it affirms the actual existence of its own body, and inasmuch as we understand by perfection the very essence of a thing, it follows that the mind passes to greater or less perfection, when it happens to affirm concerning its own body, or any part thereof, something involving more or less reality than before.

 When, therefore, I said above that the power of the mind is increased or diminished, I merely meant that the mind had formed of its own body, or of some part thereof, an idea involving more or less of reality, than it had already affirmed concerning its own body. For the excellence of ideas, and the actual power of thinking are measured by the excellence of the object. Lastly, I have added by the presence of which the mind is determined to think of one thing rather than another, so that, besides the nature of pleasure and pain, which the first part of the definition explains, I might also express the nature of desire.