6. In considering Relation we must enquire whether it possesses the community of a genus, or whether it may on other grounds be treated as a unity.
Above all, has Relation- for example, that of right and left, double and half- any actuality? Has it, perhaps, actuality in some cases only, as for instance in what is termed "posterior" but not in what is termed "prior"? Or is its actuality in no case conceivable?
What meaning, then, are we to attach to double and half and all other cases of less and more; to habit and disposition, reclining, sitting, standing; to father, son, master, slave; to like, unlike, equal, unequal; to active and passive, measure and measured; or again to knowledge and sensation, as related respectively to the knowable and the sensible?
Knowledge, indeed, may be supposed to entail in relation to the known object some actual entity corresponding to that object's Ideal Form, and similarly with sensation as related to the sense-object. The active will perform some constant function in relation to the passive, as will the measure in relation to the measured.
But what will emerge from the relation of like to like? Nothing will emerge. Likeness is the inherence of qualitative identity; its entire content is the quality present in the two objects.
From equality, similarly, nothing emerges. The relation merely presupposes the existence of a quantitative identity;- is nothing but our judgement comparing objects essentially independent and concluding, "This and that have the same magnitude, the same quality; this has produced that; this is superior to that."
Again, what meaning can sitting and standing have apart from sitter and stander? The term "habit" either implies a having, in which case it signifies possession, or else it arises from something had, and so denotes quality; and similarly with disposition.
What then in these instances can be the meaning of correlatives apart from our conception of their juxtaposition? "Greater" may refer to very different magnitudes; "different" to all sorts of objects: the comparison is ours; it does not lie in the things themselves.
Right and left, before and behind, would seem to belong less to the category of Relation than to that of Situation. Right means "situated at one point," left means "situated at another." But the right and left are in our conception, nothing of them in the things themselves.
Before and after are merely two times; the relation is again of our making.