But the ideas of the modifications of the body are in the human mind (II.

xii.), that is, in God, in so far as he constitutes the essence of the human mind; therefore the ideas of these ideas will be in God, in so far as he has the knowledge or idea of the human mind, that is (II.

xxi.), they will be in the human mind itself, which therefore perceives not only the modifications of the body, but also the ideas of such modifications.

Q.E.D.
PROP.XXIII.

The mind does not know itself, except in so far as it perceives the ideas of the modifications of the body.
Proof .-- The idea or knowledge of the mind (II.