P14: The human Mind is capable of perceiving a great many things, and is the more capable, the more its body can be disposed in a great many ways.

Dem.: For the human Body (by Post. 3 and 6) is affected in a great many ways by external bodies, and is disposed to affect external bodies in a great many ways. But the human Mind must perceive everything which happens in the human body (by P12). Therefore, the human Mind is capable of perceiving a great many things, and is the more capable {NS: as the human Body is more capable}, q.e.d.