P25: The idea of any affection of the human Body does not involve adequate knowledge of an external body.

Dem.: We have shown (P16) that the idea of an affection of the human Body involves the nature of an external body insofar as the external body determines the human Body in a certain fixed way. But insofar as the external body is an Individual that is not related to the human Body, the idea, or knowledge, of it is in God/Nature (by P9) insofar as God/Nature is considered to be affected with the idea of another thing which (by P7) is prior in nature to the external body itself. So adequate knowledge of the external body is not in God/Nature insofar as he has the idea of an affection of the human Body, or the idea of an affection of the human Body does not involve adequate knowledge of the external body, q.e.d.