E2P31D
Demonstration — Part II
Latin
Unaquæque enim res singularis sicuti humanum corpus ab alia re singulari determinari debet ad existendum et operandum certa ac determinata ratione et hæc iterum ab alia et sic in infinitum (per propositionem 28 partis I). Cum autem ex hac communi rerum singularium proprietate in præcedenti propositione demonstraverimus nos de duratione nostri corporis non nisi admodum inadæquatam cognitionem habere, ergo hoc idem de rerum singularium duratione erit concludendum quod scilicet ejus non nisi admodum inadæquatam cognitionem habere possumus. Q.E.D.
English (Elwes 1883)
Every particular thing, like the human body, must be conditioned by another particular thing to exist and operate in a fixed and definite relation; this other particular thing must likewise be conditioned by a third, and so on to infinity. (I. xxviii.) As we have shown in the foregoing proposition, from this common property of particular things, we have only a very inadequate knowledge of the duration of our body; we must draw a similar conclusion with regard to the duration of particular things, namely, that we can only have a very inadequate knowledge of the duration thereof. Q.E.D.
Modern English
Every singular thing, just like the human body, must be determined by another singular thing to exist and to act in a certain and determinate way, and that one in turn by another, and so on to infinity (E1P28). Since we have proved from this common property of singular things in the preceding proposition that we can have only a very inadequate knowledge of the duration of our own body, the same conclusion must be drawn about the duration of singular things, namely, that we can have only a very inadequate knowledge of their duration as well. Q.E.D.