P22: The human Mind perceives not only the affections of the Body, but also the ideas of these affections.

Dem.: The ideas of the ideas of the affections follow in God/Nature in the same way and are related to God/Nature in the same way as the ideas themselves of the affections (this is demonstrated in the same way as P20). But the ideas of the affections of the Body are in the human Mind (by P12), i.e. (by P11 C), in God/Nature, insofar as he constitutes the essence of the human Mind. Therefore, the ideas of these ideas will be in God/Nature insofar as he has the knowledge, or idea, of the human Mind, i.e. (by P21), they will be in the human Mind itself, which for that reason perceives not only the affections of the Body, but also their ideas, q.e.d.