the very human being who is described as possessing humanity, then there is no doubt that every person has a humanity that is his alone, and that humanity proliferates as people proliferate. On this understanding, however, your assertion that “its attachment to matter is an effect extrinsic to the essence of humanity” collapses; for humanity’s attachment to any given human is not due to something beyond his simply being human—rather, the human himself necessitates humanity.

But if by “matter” you mean the human body, or one of the body’s accidents, then the body by itself does not bear humanity; it is borne by the body together with the soul. Even supposing the body in isolation, or on the condition that the soul be connected to it, the body’s bearing of humanity would be no different from its bearing of the rest of its accidents—length, breadth, and depth. A body is a body only by virtue of such accidents and qualities, and it is obvious that these qualities multiply with the multiplication of bodies and diminish with their diminution.

These accidents cannot exist apart from the substrate in which they inhere, and it is impermissible to claim that their inherence in a substrate is not intrinsic but the result of some separate cause. An accident comes into being only in its substrate; without that substrate it would have no reality whatsoever. If it has neither existence nor quiddity in the external world, then whoever posits humanity as something subsisting outside what inheres in a human being, or claims that humanity’s attachment to the human is due to an external cause, has indeed gone astray.

Here lies one of the points at which the intellects of these people and their followers have deviated: they imagined an absolute reality for “human” (and for every other species) existing in the external world, accompanying the “matter” that—according to their terminology—is the very substance of each individual among human beings and of every other member of the species, and that by virtue of this matter the species becomes individuated. Had they been rightly guided they would have realized that what they call the “matter” constituting the individual is simply making the cause identical with the effect. Nothing exists externally save the individuals themselves; there is no reality outside them other than what they label “matter,” which in their technical usage here is matter conjoined with form—whether the form is a substance, such as the forms of animals, plants, and minerals, or whether it be