Spinoza's Ethics: II.P45

Unaquæque cujuscunque corporis vel rei singularis actu existentis idea Dei æternam et infinitam essentiam necessario involvit.

Each and every idea of whatsoever body or singular thing by means of the act of existence involves the eternal and infinite essence of God by necessity.

DEMONSTRATIO: Idea rei singularis actu existentis ipsius rei tam essentiam quam existentiam necessario involvit (per corollarium propositionis 8 hujus). At res singulares (per propositionem 15 partis I) non possunt sine Deo concipi sed quia (per propositionem 6 hujus) Deum pro causa habent quatenus sub attributo consideratur cujus res ipsæ modi sunt, debent necessario earum ideæ (per axioma 4 partis I) ipsarum attributi conceptum hoc est (per definitionem 6 partis I) Dei æternam et infinitam essentiam involvere. Q.E.D.

The idea of a singular thing involves by necessity by the act of existing of the thing itself involves not only essence but existence as well.

SCHOLIUM: Hic per existentiam non intelligo durationem hoc est existentiam quatenus abstracte concipitur et tanquam quædam quantitatis species. Nam loquor de ipsa natura existentiæ quæ rebus singularibus tribuitur propterea quod ex æterna necessitate Dei naturæ infinita infinitis modis sequuntur (vide propositionem 16 partis I). Loquor inquam de ipsa existentia rerum singularium quatenus in Deo sunt. Nam etsi unaquæque ab alia re singulari determinetur ad certo modo existendum, vis tamen qua unaquæque in existendo perseverat, ex æterna necessitate naturæ Dei sequitur. Qua de re vide corollarium propositionis 24 partis I.

Here by existence I do not understand duration, that is existence insofar as it is conceived abstractly and so to speak, a certain kind of quantity. For I speak about the nature itself of existence which is divided by singular things thus that which follow from the eternal necessity of God by infinite nature in infinite modes (see IP16). I speak, I say concerning the existence itself of singular things insofar as they are in God. For as if each and every thing is determined by some singular thing for existing by a certain mode, nevertheless the power by which each and every thing perseveres in existence, it follows from the eternal necessity of the nature of God. Concerning which see IP24C.