which in their turn are conditioned to exist and operate in a fixed and definite relation by other causes, these last again being conditioned by others, and so on to infinity. The duration of our body therefore depends on the common order of nature, or the constitution of things. Now, however a thing may be constituted, the adequate knowledge of that thing is in God, in so far as he has the ideas of all things, and not in so far as he has the idea of the human body only. (II. ix. Coroll.) Wherefore the knowledge of the duration of our body is in God very inadequate, in so far as he is only regarded as constituting the nature of the human mind; that is (II. xi. Coroll.), this knowledge is very inadequate to our mind. Q.E.D.
PROP. XXXI. We can only have a very inadequate knowledge of the duration of particular things external to ourselves.
Proof.—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.
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