Abstract

A substance is a concrete individual thing that exists all at once. Although the world can be cut up into substances in different ways, any full description of the world will include both material objects and immaterial souls as substances. Souls have essentially mental properties, ones to which the subject has privileged access such as thoughts and sensations. The essential part of a human being is a human soul, one with a structure and a capacity for logical thought, moral belief, and free will, and certain limited powers exercised through a human body. No human being is essentially human.