E3P8D
Demonstration — Part III
Latin
Si enim tempus limitatum involveret quod rei durationem determinaret, tum ex sola ipsa potentia qua res existit, sequeretur quod res post limitatum illud tempus non posset existere sed quod deberet destrui; atqui hoc (per propositionem 4 hujus) est absurdum : ergo conatus quo res existit, nullum tempus definitum involvit sed contra quoniam (per eandem propositionem 4 hujus) si a nulla externa causa destruatur, eadem potentia qua jam existit, existere perget semper, ergo hic conatus tempus indefinitum involvit. Q.E.D.
English (Elwes 1883)
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.
Modern English
If it involved a limited time that would determine the duration of the thing, then from the very power by which the thing exists it would follow that the thing could not exist beyond that limit, meaning it would have to be destroyed. But this is absurd (E3P4). Therefore the *conatus* by which a thing exists involves no definite time. On the contrary, since (E3P4) if no external cause destroys it, the thing will always continue to exist by the same power by which it already exists, and this *conatus* involves an indefinite time. Q.E.D.