(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.
Corollary .-- Hence it follows that all particular things are contingent and perishable.

For we can have no adequate idea of their duration (by the last Prop.), and this is what we must understand by the contingency and perishableness of things.

(I.
xxxiii., Note i.) For (I.xxix.), except in this sense, nothing is contingent.
PROP.XXXII.

All ideas, in so far as they are referred to God, are true.
Proof .-- All ideas which are in God agree in every respect with their objects (II.vii.