ABSTRACT
The study of the human soul principally consists in the study of its various powers. In the case of a human being, this includes the various powers for respiration, nutrition, growth, and reproduction—powers that even the soul of a plant possesses. As with philosophers, Thomas Aquinas is interested more in conceptual questions regarding the nature of sense and intellect than in the physical processes that underlie capacities. At the sensory level, Aquinas distinguishes five external senses, so called because these are the cognitive powers that most directly receive external stimulus. Those are Sight: Color, Hearing: Sound, Smell: Odor, Taste: Flavor and Touch: Temperature. The most obvious way in which sense and intellect work together is that the senses supply the data used by intellect to form universal concepts. Aquinas's most extensive discussions of the topics come in his commentary on Aristotle's De anima and in the Treatise on Human Nature.
