intrinsically prior to it—for the part precedes the whole, and the simple precedes the composite—,” and what is meant by this is composition in external reality, then all of this is confusion. An attribute is dependent upon its subject, so how could it precede that subject in any respect?

If it is said, “A human being is composed of animality and rationality, or of an animal and a rational being,” and what is meant is that it is composed of two substances subsisting in themselves, it would follow that every subject contains as many substances as it has attributes. Thus, within a human being there would be one substance that is a body, another that is sentient, another that grows, another that moves voluntarily, and another that is rational.

It is well known that this is false. Rather, a human being is a substance subsisting in itself and characterized by these attributes. It is therefore described as a body that is sentient (1), growing, voluntarily moving, and rational.

If what is meant [by this] (2) is that it is composed of two accidents, then a human being is a substance, and a substance is not composed of accidents that inhere in it, much less of accidents that precede it and are prior to it.

We have discussed all of this at length elsewhere. The purpose here is only to show that these philosophers frequently err by treating intelligible mental entities conceived within the soul as the very same entities that exist in external reality. The Pythagoreans, who asserted the existence of abstract numbers in external reality, erred for precisely this reason (3),