say expressly that the mind has no adequate knowledge of itself, nor
of its body, nor of external bodies, but only a confused knowledge, as
often as it perceives things in the common order of Nature, that is to
say, as often as it is determined to the contemplation of this or that
_externally_--namely, by a chance coincidence, and not as often as it is
determined _internally_--for the reason that it contemplates several
things at once, and is determined to understand in what they differ,
agree, or oppose one another; for whenever it is internally disposed in
this or in any other way, it then contemplates things clearly and
distinctly.

III

The duration of our body does not depend upon its essence, nor upon the
absolute nature of God, but the body is determined to existence and
action by causes which also are determined by others to existence and
action in a certain and determinate manner, whilst these, again, are
determined by others, and so on _ad infinitum_. The duration, therefore,
of our body depends upon the common order of Nature and the constitution
of things. But an adequate knowledge of the way in which things are
constituted, exists in God in so far as He possesses the ideas of all
things, and not in so far as He possesses only the idea of the human
body. Therefore the knowledge of the duration of our body is altogether
inadequate in God, in so far as He is only considered as constituting
the nature of the human mind, that is to say, this knowledge in our mind
is altogether inadequate.

Each individual thing, like the human body, must be determined to
existence and action by another individual thing in a certain and
determinate manner, and this again by another, and so on _ad infinitum_.
But we have demonstrated in the preceding proposition, from this common
property of individual things, that we have but a very inadequate
knowledge of the duration of our own body; therefore the same conclusion
is to be drawn about the duration of individual things, that is to say,
that we can have but a very inadequate knowledge of it.

Hence it follows that all individual things are contingent and
corruptible, for we can have no adequate knowledge concerning their
duration and this is what is to be understood by us as their contingency
and capability of corruption; for there is no other contingency but
this.

_The Mind's Knowledge of God_

The idea of an individual thing actually existing necessarily involves
bo