II. The human body can undergo many changes, and, nevertheless,
retain the impressions or traces of objects (cf. II. Post. v.),
and, consequently, the same images of things (see note II.
xvii.).

PROP. I. Our mind is in certain cases active, and in certain
cases passive. In so far as it has adequate ideas it is
necessarily active, and in so far as it has inadequate ideas, it
is necessarily passive.

Proof.--In every human mind there are some adequate ideas, and
some ideas that are fragmentary and confused (II. xl. note).
Those ideas which are adequate in the mind are adequate also in
God, inasmuch as he constitutes the essence of the mind (II. xl.
Coroll.), and those which are inadequate in the mind are likewise
(by the same Coroll.) adequate in God, not inasmuch as he
contains in himself the essence of the given mind alone, but as
he, at the same time, contains the minds of other things. Again,
from any given idea some effect must necessarily follow (I. 36);
of this effect God is the adequate cause (III. Def. i.), not
inasmuch as he is infinite, but inasmuch as he is conceived as
affected by the given idea (II. ix.). But of that effect whereof
God is the cause, inasmuch as he is affected by an idea which is
adequate in a given mind, of that effect, I repeat, the mind in
question is the adequate cause (II. xi. Coroll.). Therefore our
mind, in so far as it has adequate ideas (III. Def. ii.), is in
certain cases necessarily active; this was our first point.
Again, whatsoever necessarily follows from the idea which is
adequate in God, not by virtue of his possessing in himself the
mind of one man only, but by virtue of his containing, together
with the mind of that one man, the minds of other things also, of
such an effect (II. xi. Coroll.) the mind of the given man is not
an adequate, but only a partial cause; thus (III. Def. ii.) the
mind, inasmuch as it has inadequate ideas, is in certain cases
necessarily passive; this was our second point. Therefore our
mind, &c. Q.E.D.

Corollary.--Hence it follows that the mind is more or less
liable to be acted upon, in proportion as it possesses inadequate
ideas, and, contrariwise, is more or less active in proportion as
it possesses adequate ideas.

PROP. II. Body cannot determine mind to think, neither can mind
determine body to motion or rest or any state different from
these, if such there be.

Proof.--All modes of thinking have for their cause God, by
virt