THE FIRST WAY: A REJOINDER

William A. Wallace, O.P.

The Catholic University of America

Washington, D. C.

IN THE PRECEDING article Professor John King-Fallow has raised a number of intriguing questions relating to the prima via of St. Thomas Aquinas--questions, indeed, that cannot be answered with any measure of completeness in a brief reply. The queries he raises, however, do present the opportunity to offer some further observations on the traditional understanding of the proof and on its validity in the light of modern science, and these will be the focus of this rejoinder.

The prima, via, it would seem, is a clear instance of a cosmological argument for the existence of God. It starts from an observable aspect of the cosmos, i. e., the motion or movement or change that is sensibly observable in it, reasons a posteriori from this to an ultimate cause, and so concludes to the existence of a First Unmoved Mover who is incorporeal, immaterial, infinite in power, etc., and who in the sequel can be identified with the God of Revelation. Although in its later stages the proof makes use of metaphysical reasoning, its beginnings actually pertain to natural philosophy. (Indeed, as most Thomists hold, if the natural philosopher could not prove the existence of some type of being that really exists and is neither material nor in motion, there would be no need for metaphysics as a discipline, since its subject matter would be essentially the same as that of natural philosophy.) The natural philosopher, moreover, abstracts from certain features of the physical world in elaborating his discipline; this abstractive process is found in all sciences, although some abstract in ways different from others, and their manner of abstracting can unfortunately have a restrictive influence on the types of arguments and proofs they are able to elaborate.¹

¹ For a succinct account of Thomistic teaching on abstraction and its relation to the classification of the sciences, see the articles by E. D. Simmons entitled "Abstraction " and " Sciences, Classification of " in the New Catholic Encyclopedia, 16 vols. (New York: McGraw-Hill and Publishers Guild, Inc., 1967, 1974), Vol. 1, pp. 56-59, and Vol. 12, pp. 1220-1224.

On this understanding the prima via is only one of several possible cosmological arguments, all of which, precisely as cosmological, operate at the same " degree " of abstraction. Thus the secunda via, the tertia via, and the quinta via may be viewed as different proofs,² complementary in some respects, following the same basic logic or methodology, each of equal abstractness, and yet each capable of independent formulation and justification.³ Moreover, insofar as these proofs focus attention successively on particular aspects of the cosmos, it is admittedly quite legitimate to say that each one " abstracts from " other aspects of the same cosmos. Such a use of the notion of " abstraction," however, is different from the way in which the abstractive process may be said to differentiate the sciences. King-Farlow calls attention to my frequent use of the terms " abstract " and " abstraction " and makes a play on these expressions in urging his own interpretation of the prima via--one essentially at variance with that given it in the Thomistic tradition. The difference between his use of " abstraction " and mine is that he gives the term the rather broad, precisive meaning just illustrated, whereas I use it in the technical Aristotelian-Thomistic way employed to differentiate the various sciences.⁴

² Here the quarta via is consciously omitted as being more metaphysical in character than the other four ways.

³ My affirmation of the partly complementary character of the proofs is shared by King-Farlow in his books Reason and Religion and Faith and the Life of Reason. He would stress, however, that the proofs are only collectively valid, whereas I am further claiming their individual validity. See notes 4 and 13, infra.

⁴ Correspondence with King-Farlow shows that we agree to disagree on this matter of " abstractness " thus. A description D1 is a more abstract description of the world W than is description D2, when D1 covers fewer sets of predicates required for indicating the most important features of W. It is Aquinas's claim and mine that the existence of a physical universe to which predicates of the natural sciences, N_1, N₂. . . ,N_n, are truly applied offers sufficient reason to affirm the existence of a Being to whom related predicates can be assigned and who is identifiable with the God of Revelation. It is King-Farlow's view that some ethical predicates, E₁, etc., as well as N₁, etc., must be applicable if sufficient reason is to be given. This accents, in a different way, our basic difference over the merely collective validity as opposed to the individual and collective validity of the proofs.

To be more specific, the over-riding concern in my articles cited by King-Farlow has been with mathematical reasoning and the mathematical physics this generates, which Thomists commonly think of as operating (at least partially) at the " second degree " of abstraction, i. e., an abstraction that leaves aside sensible matter and motion and concentrates exclusively on the quantifiable aspects of natural phenomena, which aspects are refractory to analysis in terms of efficient and final causality. The natural philosopher, as opposed to this, operates at the " first degree " of abstraction, i. e., one that leaves aside only the individual aspects of natural phenomena so as to consider them universally, but still as involving sensible matter and motion in their definition, and for this reason open to the discovery of agents and ends. All cosmological arguments, to the extent that they are cosmological and in this sense pertain in some way to natural philosophy, may be seen as functioning (at least in their initial stages) at this first degree of abstraction. It is preferable, on this account, not to speak of the ways in which the various cosmological proofs differ among themselves as differences of " abstraction " or of " abstractness." Here the Thomistic tradition appears to be at odds with King-Farlow, who in the foregoing article speaks first of the prima via " in physical space " and then of the same proof " in moral space." Seemingly he regards the latter consideration as less " abstract " than the former and as more appealing, on that account, to the Christian theist because of its openness to moral and personal values. In the traditional view neither of these considerations is more " abstract " than the other; what is important is that they are precisive of different aspects of the world of nature and thus may provide the basis for different cosmological proofs. So, when King-Farlow speaks of " the prima via in physical space," most of what he says is unexceptional, for he is talking about the prima via as Thomists have

generally understood it; when he speaks of the same proof " in moral space," on the other hand, it is somewhat difficult to follow his argument. In this second manner of speaking he may well be on the track of a valid proof for God's existence, but if so, one would not wish to call this new proof the prima via. Perhaps what he is proposing there is a nuanced version of the quinta via, or alternatively, he may be working out a sexta via, or a septima via, etc. In my published writings, as opposed to this, I have dealt exclusively with the prima via in its traditional understanding and resist being drawn into a related area of discourse, however enlightening this might be to the Christian theist, particularly when much yet remains to be done in the domain of " physical space "--as King-Farlow himself has effectively shown.

To concentrate, then, on the first part of the foregoing article, the question of the finitude of physical space or of physical movers and things moved) is certainly integral to both Aristotle's and Aquinas's arguments for the existence of a First Unmoved Mover. The difference between the arguments lies in the fact, as is well known, that Aristotle was convinced of the infinite duration of the universe whereas Aquinas believed in its creation in time and thus in its temporal finitude; for purposes of argument, however, Aquinas was willing to admit the theoretical possibility of an infinite temporal regress, and so his argument does not develop in a way essentially different from Aristotle's.⁵ Both thinkers, moreover, thought of the hierarchy of movers and moveds in the context of what is now referred to as a Ptolemaic universe, i. e., a closed world of finite dimensions and composed of a finite number of concentric spheres. In such a universe no physical body can be actually infinite, although, as King-Farlow rightly discerns, physical bodies can be thought of as made up of a potentially infinite number of parts, when they are either divided into, or

⁵ A fuller exposition of Aquinas's view on the temporal finitude of the universe is given in my article, " Aquinas on Creation: Science, Theology, and Matters of Fact," The Thomist, 38 (1974), pp. 485-523.

addition is made to them by means of, proportional parts--the type of geometrical progression favored by peripatetics and illustrated so well in King-Farlow's article.⁶ For the cosmologist of the present day, of course, the context is quite different and so the problematic must also be stated differently. It is precisely his awareness of this situation that has led Anthony Kenny to reject the Five Ways as hopelessly imbedded in a medieval cosmology.⁷ One need not agree with Kenny's pessimistic evaluation,⁸ however, and in fact one can be quite sympathetic to King-Farlow's analysis above, for the concept of potential infinity may well prove adequate to handle objections arising from modern mathematical theories of the universe. This adequacy cannot be assumed, however, and requires more detailed argument and substantiation than could possibly be given in this rejoinder.

Apart from the problem of the finitude of the physical universe, there are other special difficulties associated with the prima via that arise in the context of modern physics and that perforce could not have been considered by either Aquinas or Aristotle. The thorniest problem would seem to be that posed by inertial motion and the way in which this threatens the general applicability of the Aristotelian-Thomistic thesis on the simultaneity of cause and effect (or of mover and thing moved) to the elimination of the infinite regress possibility. Some aspects of this problem have been examined in the article on Newtonian antinomies cited by King-Farlow, but one of my more recent publications also takes note of a number of texts where Aquinas admits the possibility of antecedent (i. e.,

⁶ Some aspects of King-Farlow's exposition, it may be noted, are adumbrated in late medieval and scholastic discussions of infinity see especially Domingo de Soto, Super octo libros physicorum Aristotelis questiones, 2d ed. (Salamanca: Andrea a Portonariis, 1555), fols. 52r-58r.

⁷ The Five Ways (London: Routledge & Kegan Paul, 1969), p. 3.

⁸ See my review of this in The Thomist, 36 (1972), pp. 721-724, as well as the article cited by King-Farlow, " The Cosmological Argument: A Reappraisal," Proceedings of the American Catholic Philosophical Association, 46 (1972), pp. 43-57.

non-simultaneous) causality in physical processes.⁹ To my knowledge Aquinas nowhere resolves the enigmas that such an admission creates for the prima via, although a resolution appears generally possible and needs only to be worked out in detail for types of causal regress that interest the modern physicist. In fairness to Kenny, moreover, it should be admitted that contemporary Thomists have not adequately answered the questions he raises relating to the motor-causality principle and the infinite regress as applicable to cases that have arisen in recent science. This failure would seem to be traceable in no small part to the proclivity of Thomistic metaphysicians to answer every objection to theistic proofs in terms of being and the act of existing, and to their failure, as a consequence, to take a close look at the world of nature. If they pretend to offer cosmological arguments at all, unfortunately they do so in terms of what the late R. J. Nogar referred to as a " cosmology without a cosmos," ¹⁰ one that is clearly at variance with both the spirit and the letter of Aquinas himself. On this account it is refreshing to see King-Farlow addressing himself to these concrete cosmological problems--for it is only by solving them that one can promote acceptance of the prima via by the modern mind.¹¹

With regard to the apparently abrupt dismissal of the second part of King-Farlow's article, the following clarification may now be in order. The introduction of a moral dimension into discussions of the prima via is particularly distasteful to me because it inadvertently concedes too much to the two philosophers who have made the prima via unappealing to our contemporaries, namely, David Hume and Immanuel Kant. As

⁹ "Aquinas and the Temporal Relation Between Cause and Effect," The Review of Metaphysics, 27 (1974), pp. 569-584.

¹⁰ See his essay of that title in From an Abundant Spring. The Walter Farrell Memorial Volume of The Thomist (New York: P. J. Kenedy, 1952), pp. 363-391.

¹¹ I also endorse King-Farlow's view that, if modern commentators like Copleston and Kenny present Aquinas over-sympathetically in failing to stress Aristotle's pertinent view on the finitude of space, then they offend fewer modern physicists, but they seriously misrepresent St. Thomas's own reasoning. Now is a good time for us both to stress this.

argued in my second volume on Causality and Scientific Explanation,¹² neither Hume nor Kant was consistent in his understanding of causality, and each effectively adopted a subjectivist approach to knowledge reached through causal analysis. For Hume causality became nothing more than a psychological projection into reality, a matter of " feeling " or of human anticipation, whereas for Kant it became an a priori category of the understanding that would serve to organize phenomena but could yield no knowledge of any reality behind the appearances. For both, therefore, a posteriori demonstration became an impossibility, as did any science of nature in the epistemic (as opposed to the empiriological) sense, and cosmological proofs for God's existence could lead at best to transcendental illusion. Thus for them the way to God through the intellect and its understanding of the universe was effectively blocked, and if one wished to assent to God's existence he would have to do so on moral or affective grounds. (This is not to deny, of course, the validity of theistic proofs based on such ethical and valuational grounds, but it does oppose reducing all proofs to this kind, and particularly the prima via.¹³)

As noted in the recently published supplement to the New Catholic Encyclopedia,¹⁴ both Hume and Kant tried to elaborate

¹² (Ann Arbor: The University of Michigan Press, 1974), pp. 38-51, 60-75.

¹³ The fundamental difference between myself and King-Farlow on this point has been well put by him in our correspondence, as follows: " You take the Five Ways to be complementary and individually adequate; I take them to be complementary and collectively imposing. You think of deductively sound demonstrations; I think in terms of ' Good Reasons ' arguments which wise people can come to find overwhelming. Hume and Kant may have sometimes thought that reasoning with normative premises is the soft underbelly of philosophical theology as they understood it. But the enthymematic premise that some arguments are good and some are bad, some wise, some foolish, etc., then becomes the soft underbelly of all intelligent reasoning, including Hume's and Kant's. As I argue in Faith and the Life of Reason, the ' positivist ' attack on the ethical dimension of what we seem to experience generalizes itself into an attack on all normative dimensions. But this could only be sound if it is unsound--that is, if we know
some reasoning to be good, bad, worthy of attention, dishonest, etc."

¹⁴ In my article entitled " Cosmological Argument," Vol. 16, pp. 105-108.

philosophies of science, but they did so only in a context provided by classical mechanics, and their efforts have proved singularly sterile for evaluating realist claims arising from high-energy physics. The discovery of vast numbers of so-called " elementary particles," with non-classical properties that render them unobservable even in principle, suggests that scientists are now (contra Hume and Kant) de facto employing causal reasoning to transcend sense experience and to arrive at deeper ontological explanations of the physical universe. Such scientists, rather than recent philosophers of empiricist and analytical bent, are the thinkers who are developing canons of demonstrative inference that can be used to establish the existence and attributes of entities unlike those falling under sense observation. In this they have much in common with Aquinas and with the type of reasoning he employed to elaborate the quinque viae. The obvious task awaiting those of us who are interested in defending cosmological proofs for God's existence is to refine and complement their methodology and show how it can sustain a plausible inference to such a transcendent cause. And, as has been suggested in the same supplement,¹⁵ such an enterprise must be directed, not to the " religious " person who regards his commitment to God as an affair of his heart or will and not of his intellect but rather to the hard-headed thinker who uses his mind to study the world of nature in objective fashion and so to penetrate to its underlying causes.

This is not to say, of course, that King-Farlow would be unsympathetic to such a program. But he will probably agree that it would have to avoid pursuing some of the leads he suggests in the second part of his article so as to devote full time to clearing up the difficulties he raises in the first.

¹⁵ Ibid., pp. 107-108.