Stage III

However, in the self-movers that exist among us—in animals, I mean—the part that does the moving—the soul—is moved per accidens even if it is immovable per se. And so Aristotle shows, further, that in a first self-mover the part that does the moving is not

moved, neither per se nor per accidens.

For since the self-movers that exist among us—animals—are destructible, the part in them that acts as a mover is moved per accidens. Now it is necessary that destructible self-movers be traced back to some first self-mover that is sempiternal. Therefore, it is necessary that some self-mover have a mover that is not moved,

neither per se nor per accidens.

51 Cf. Physics VIII 6, 258bl0-16; In Phys. VIII: L12.1069-71

Now it is clearly necessary from Aristotle's point of view that some self-mover be sempiternal. For if motion is sempiternal, as he supposes, the generation of self-movers that are generable and destructible must be perpetual. But none of those self-movers can be the cause of this perpetuity, because none of them exists always. Nor [can] all of them together [be its cause], both because there would be infinitely many of them and because they do not exist simultaneously. We are left, therefore, with the conclusion that there must be some perpetual self-mover that causes the perpetuity of generation as regards those inferior self-movers. And so its mover is not moved,

neither per se nor per accidens.

52 Cf. Physics VIII 6, 258b23-259a21; In Phys. VIII: L12.1074-6.

Again, as regards self-movers, we see that some of them begin to be newly moved because of some motion with which the animal is not moved by itself, as when it is awakened from sleep by digested food

or a change in the air

53 The editors of the Marietti edn. add the words cum excitatur a somno ('when it is awakened from sleep'), omitted by the Leonine editors, although they appear in all but two of the manuscripts used for the edn. The inclusion of those words is further Justified by the parallel passage in In Phys. VIII: L13.1080, as the Marietti editors point out in a note at this point.

—a motion with which that self-mover itself is, of end p.77


© Copyright Oxford University Press, 2006. All Rights Reserved course, moved per accidens. From this we can gather that no self-mover whose mover is moved either per se or per accidens is moved always. A first self-mover, however, is moved always; otherwise motion would not be sempiternal, since every motion other than a first self-mover's motion is caused. We are left, therefore, with the conclusion that a first self-mover is moved by a mover that is not

moved, neither perse nor per accidens. (13.103-6)

these immediately following lines: 'And it does not count against this argument that the movers of the lower spheres move a sempiternal motion and yet are said to be moved per accidens. For they are said to be moved per accidens not by reason of themselves but by reason of the things movable by them, which follow the motion of a higher sphere' (13.107; cf. Physics VIII 6, 259b28-31; In Phys. VIII: L13.1082).

I think it's clear that human beings are among the animals under consideration in stage III. In the parallel passage of the Physics commentary Aquinas indicates plainly that both human and non-human animals are


55 In In Phys. VIII: L12.1070-1 Aquinas introduces the parallel to G2's stage III with allusions to intellect that help to show that he takes the argument to apply to, if not to focus on, human animals. And by his reference to animals with destructible souls in the same context, he indicates that it is intended to apply also to non-human animals: 'in connection with the self-movers we are familiar with—I mean, destructible animals—it can be the case that the part that does the moving in the self-mover—the soul—is destructible and is moved per accidens' (VIII: L12.1069).

In any case, I propose to consider stage III in terms of human beings.

Stage II's analysis shows that in anything that might be strictly considered a self-mover the part that does the moving, considered just as such, must be immovable, both per se and per accidens. Stage III begins by observing that this is not what we find in the only 'self-movers' we are familiar with, including ourselves. A human being's rational soul, its intellect and will, is the part that does the moving of the human being, and it is movable per accidens.

What he means here by a soul's being moved per accidens is best determined by the evidence he provides, the most accessible of which is based on ordinary observation (lines 23-7). Human sleeping and waking are most particularly states of the rational soul (of the sensory soul to a lesser degree, and of the nutritive soul not at all). The waking of a human being 'by digested food or a change in the air' involves the rational soul's being moved per accidens intrinsically by a motion in the nutritive or the sensory soul, which was in turn moved per accidens extrinsically. And the fact that the being moved is from sleep to wakefulness helps to ensure that the end p.78


© Copyright Oxford University Press, 2006. All Rights Reserved part of the human being that does the moving on such an occasion isn't somehow the rational soul itself. In this way even the indestructible rational soul proves to be relevantly movable per accidens, so that in its own active moving (of the body) it is to some extent passively subjected to the vicissitudes of the external world via the nutritive or the sensory soul. And if not even the rational soul, the distinctively human intrinsic mover, is an immovable intrinsic mover, then there are no genuine self-movers among the things we are familiar with. Anything that might count as a cosmic first self-mover would have to be unlike the 'self-movers' we know, in being immovable even per accidens as regards the part that does the moving, in the sense that it would have to be impervious to any extrinsic efficient causation.

The absolute unmovedness of any first mover that might count as (or come close to counting as) God is only one of two points aimed at in stage III. The other is the beginninglessness of any viable candidate. The Aristotelian thesis that motion is sempiternal (line 13) is of course crucial to this aspect of stage III. But it is only the beginninglessness and continuity implicit in sempiternity that are relevant here (and not also its endlessness), and so we can focus our attention appropriately by reading Aquinas's 'sempiternal', 'perpetual', and 'always' as 'beginningless' or 'beginninglessly', and his

'perpetuity' as 'beginninglessness'.

56 He uses sempiternum in 13.104-7, perpetua and perpetuitas in 105, semper in 105 and 106, and aeternitas (as synonymous with perpetuitas or sempiternitas) in 109 and 110.

Stage III is developing the hypothesis that motion is to be explained in terms of self-movers, and that all motion is ultimately to be explained in terms of a cosmic first self-mover. Aquinas says that if motion is beginningless, then the generation of self-movers that are generable and destructible must be beginningless (lines 13-15). For my purposes in this strand of stage III we can generalize the Aristotelian hypothesis to something like this: the generative series of generable and destructible natural things—that is, the physical universe considered diachronically—is beginningless. That hypothesis is, I think, compatible not only with stage III but also with all

varieties of cosmic evolution.

57 Even if empirical data render the Big Bang hypothesis undeniable, a beginningless universe with a beginningless process of cosmic evolution is not thereby ruled out, as cosmologists' considerations of a 'concertina' universe indicate.

end p.79


© Copyright Oxford University Press, 2006. All Rights Reserved

Notice that this strand of the argument is concerned not with the source of any element or elements of the generative series, or even directly with the cause of the series itself, but rather with the cause or explanation of its beginninglessness (cf. lines 15-16, 19-20). What could account for there having been movers always? Aquinas is surely within his rights to suppose that if X accounts for Y's existing beginninglessly, then X itself cannot have begun to exist (lines 15-16). But suppose we do think of the beginningless generative series as the physical universe itself. We will then recognize that, in view of its beginninglessness, none of the infinitely many generative events making up the series lacks an explanation in the form of an extrinsic moved mover. And so the presupposition here is that there is some explanation of the very fact that there is this beginningless series of moved movers. Why is there what there is, rather than something else or nothing at all? Those who share my view that this question is not merely rhetorical will find that presupposition unexceptionable. As for those who say they don't share that view, I find it very hard to believe that they aren't kidding themselves, especially because they, like all the rest of us, recognize that rational inquiry, if not quantum physics, depends on taking particular instantiations of that question seriously in every other context. Every cosmological argument depends on some version of the principle of sufficient reason, and the version on which this one depends strikes me as prima facie irresistible and pragmatically defensible: 'if there is a cause of the generation and destruction of things that move themselves, there must also be a cause of the fact that their generation and destruction is perpetually continuous' (In Phys. VIII: LI2.1074).

The rest of this strand of stage III is devoted to ruling out (a) any element or elements of the beginningless series (lines 15-16) and (b) all its elements taken together (lines 16-18) as possibly explanatory of its beginninglessness, and I see no good grounds on which to object to this development. The familiar objections raised by Hume and Russell against this line of reasoning in cosmological arguments have been decisively

answered in well-known work by William Rowe,

58 See e.g. Rowe 1975c. some of which we'll be considering in another connection in the next chapter. But the exclusion of those other possibilities isn't all that goes on in the rest of stage III, which end p.80

Kretzmann, Norman , (deceased) formerly Susan Linn Sage Professor Emeritus of Philosophy, Cornell University, New York

Was this article helpful?

0 0
Study Aid

Study Aid

This Book Is One Of The Most Valuable Resources In The World When It Comes To Getting A Scholarship And Financial Support For Your Studies.

Get My Free Ebook

Post a comment