xiii.) it does not agree with the nature of the mind adequately; therefore (I.Ax.

vi) the idea of this idea does not adequately express the nature of the human mind, or does not involve an adequate knowledge thereof.
Corollary .-- Hence it follows that the human mind, when it perceives things after the common order of nature, has not an adequate but only a confused and fragmentary knowledge of itself, of its own body, and of external bodies.

For the mind does not know itself, except in so far as it perceives the ideas of the modifications of body (II.

xxiii.).

It only perceives its own body (II.