anything in the world is impossible, which is the point to be established. If it is possible, then either it is the more perfect alternative or it is not. If it is the more perfect, then necessarily nothing should come into existence, for bringing anything into being at that point would be a departure from what is more perfect, and that is impossible. If it is not the more perfect, then its opposite is—namely, bringing one thing after another into being—and so no act would be beginningless.

The only objection that can be raised against this is one whose invalidity is well known. It is to say:

Nothing other than this was possible: the celestial sphere could not have come into existence later, nor could any temporally originated thing have been beginningless.

The reply is:

If you mean that this is intrinsically impossible, that is mere obstinate denial. For if one supposed a celestial sphere before the sphere, and another before that, the impossibility of this would be no greater than the impossibility of the sphere’s existing perpetually. Indeed, if a single member of a species can exist perpetually, then the perpetuity of the species is all the more possible.

It is therefore inconceivable (1) that a single human being should be beginningless and eternal while it is impossible for the human species to be beginningless through one individual succeeding another.

If, however, you suppose that it is impossible due to some extrinsic consideration—such as the presence of an opposing factor, the absence of any wise purpose on the Agent’s part, or the like—then whatever precludes the beginninglessness of a kind of effect is even more incompatible with the beginninglessness of a particular instance of it. If the beginninglessness of its particular instance is admissible, then the beginninglessness of the kind through the successive origination of individual instances is even more admissible. If the latter is impossible, the former is all the more impossible. Moreover, anything that necessitates the temporal origination of the individual instances of some effects that could be beginningless likewise necessitates the temporal origination of its counterpart.

Suppose, then, that they say:

Motion, by its very nature, cannot persist, whereas temporally originated things consist of numerous substances, one after another. Thus, if the four elements can be beginningless—