PROP. XXXVII. That which is common to all (cf. Lemma II., above), and which is equally in a part and in the whole, does not constitute the essence of any particular thing.

Proof.—If this be denied, conceive, if possible, that it constitutes the essence of some particular thing; for instance, the essence of B. Then (II. Def. ii.) it cannot without B either exist or be conceived; but this is against our hypothesis. Therefore it does not appertain to B’s essence, nor does it constitute the essence of any particular thing. Q.E.D.