e knowledge of each part composing the human body exists in
God in so far as He is affected by a number of ideas of things, and not
in so far as He has the idea of the human body only; that is to say, the
idea which constitutes the nature of the human mind; and therefore the
human mind does not involve an adequate knowledge of the parts composing
the human body.

We have shown that the idea of a modification of the human body involves
the nature of an external body so far as the external body determines
the human body in some certain manner. But in so far as the external
body is an individual which is not related to the human body, its idea
or knowledge is in God, in so far as He is considered as affected by the
idea of another thing, which idea is prior by nature to the external
body itself. Therefore the adequate knowledge of an external body is not
in God in so far as He has the idea of the modification of the human
body, or, in other words, the idea of the modification of the human body
does not involve an adequate knowledge of an external body.

When the human mind through the ideas of the modifications of its body
contemplates external bodies, we say that it then imagines, nor can the
mind in any other way imagine external bodies as actually existing.
Therefore in so far as the mind imagines external bodies it does not
possess an adequate knowledge of them.

II

The idea of a modification of the human body does not involve an
adequate knowledge of the body itself, or, in other words, does not
adequately express its nature, that is to say, it does not correspond
adequately with the nature of the human mind, and therefore the idea of
this idea does not adequately express the nature of the human mind, nor
involve an adequate knowledge of it.

From this it is evident that the human mind, when it perceives things in
the common order of Nature, has no adequate knowledge of itself nor of
its own body, nor of external bodies, but only a confused and mutilated
knowledge; for the mind does not know itself unless in so far as it
perceives the ideas of the modifications of the body. Moreover, it does
not perceive its body unless through those same ideas of the
modifications by means of which alone it perceives external bodies.
Therefore in so far as it possesses these ideas it possesses an adequate
knowledge neither of itself, nor of its body, nor of external bodies,
but merely a mutilated and confused knowledge.

I