¹ Feser, Edward, “Between Aristotle and William Paley: Aquinas's Fifth Way”, Nova et Vetera, 11, 3, (Summer 2013), pp. 707-08Google Scholar.

² See Feser, “Between Aristotle and William Paley,” p. 740.

³ Feser, “Between Aristotle and William Paley,” p. 709.

⁴ Aquinas never uses the expression “immanent teleology.” He speaks rather of “natural appetite” which he defines thus: “natural appetite is nothing other than the ordering of some things according to their own nature to their end” (In Octo Libros de Physico Auditu Commentaria, ed. M., Angeli O.P., Pirotta, [Naples: M. D'Auria Pontificius Editor, 1953)Google Scholar, Bk. 1, lec. 15, #276]. All translations of Aquinas are my own. Unless otherwise noted, all texts from Aquinas are drawn from the online Corpus Thomisticum, ed. Enrique Alarcón, University of Navarre, http://www.corpusthomisticum.org/iopera.html.

⁵ Feser, “Between Aristotle and William Paley,” p. 714.

⁶ Summa Theologiae, ed. Instituti Studiorum Medievalium Ottaviensis (Ottawa: Commissio Piana, 1953), I, q. 2, a. 3: “Quinta via sumitur ex gubernatione rerum. Videmus enim quod aliqua quae cognition carent, scilicet corpora naturalia, operantur propter finem; quod apparet ex hoc quod semper aut frequentius eodem modo operantur, ut consequantur id quod est optimum; unde patet quod non a casu, sed ex intentione perveniunt ad finem. Ea autem quae non habent cognitionem, non tendunt in finem nisi directa ab aliquo cognoscente et intelligente, sicut sagitta a sagittante. Ergo est aliquid intelligens, a quo omnes res naturales ordinantur ad finem, et hoc dicimus Deum.” (Hereafter cited as ST.)

⁷ Aquinas elsewhere makes it plain that the notion of tending to an end [“intendere finem”] is not restricted to natural things: “to tend [intendere] to is to tend to something [in aliud tendere], which certainly belongs to the mover and to the thing moved. Therefore, according as to tend to an end [intendere finem] is said of that which is moved by another, in this manner nature is said tend to an end, as moved to its end by God, as an arrow by an archer” (ST I-II, q. 12, a. 5).

⁸ Edward Feser, “Teleology: A Shopper's Guide”, Philosophia Christi, 12, 1, (2010), p. 156. Note how Feser here conflates final causality with immanent end-directedness. Final causality is plainly present in artifacts as well, something which Feser terms “extrinsic teleology.”

⁹ ST I 2.3. Leszek Figurski, like Feser, maintains that the first part of the Fifth Way “concludes that the only sufficient explanation for the regular activity of non-cognitive natural bodies is some built-in intrinsic orientation of their natures, as agents, toward their proper ends” (Finality and Intelligence [Wydawnictwo Bezkresy Wiedzy, 2014], p. 123). But again, this view does not fit with the way the Fifth Way is worded.

¹⁰ Aquinas uses the arrow at least a dozen times to illustrate the need for a thing lacking knowledge that tends to an end to be directed by a knowing being. This can be verified by searching “sagitta” in the Index Thomisticus. To give one example: “It is necessary that the first agent, however, be an agent through intellect and will: for those things which lack intellect act for an end as directed to the end by another. Which certainly is manifest in artificial things: for the motion of the arrow to a determinate target is from the direction of the archer. It is necessary, however, that the like is found in natural things” (Summa contra Gentiles, Bk. 2, c. 23). Aquinas would seem to favor this example because it parallels the action for an end of simple natural bodies, and not just complex ones, e.g., a stone tending downwards. Perhaps he also favors it because “tendere” is a verb typically used with “arrow,” as in “tendere sagittas arcu,” in which case it means “to shoot;” it also means “to direct one's course towards,” “to go towards,” and “to be inclined” (Cassell's Latin Dictionary, revised by Marchant, J. R. V. and Charles, Joseph F. [New York: Fund & Wagnalls, 1953)Google Scholar].

¹¹ Note that Aquinas gives an argument very similar to the Fifth Way in the Summa contra Gentiles (III 63) in which he concludes that God governs the world by providence; neither argument makes reference to “immanent teleology.” Note also that Aquinas gives an argument for “some intellect” in De Veritate, q. 2, a. 3 that is based on natural appetite and not generically on tendency to an end, and for this reason seems like the sort of argument Feser takes the Fifth Way to be. It would be worthwhile to compare these arguments. The De Veritate argument reads: “For, it is necessary that everything that naturally tends to some other thing has this from some being directing it to [this] end; otherwise it would tend to it by chance. We find, however, in natural things a natural appetite, by which each and every one of them tends to its end; whence it is necessary to posit some intellect above all natural things which will have ordered natural things to their ends, and placed in them the natural inclination or appetite.” It would also be worth further investigating how the Fifth Way, which is taken “from the governance of things,” relates to the question of ST I, q. 103, a. 1, “Whether the World is Governed by Someone.” In the response to objection three, Aquinas introduces the distinction of how artificial things receive their ordering to an end and how natural ones do. I am not denying the importance of this distinction in understanding God's governance, but am simply maintaining that it plays no role in the Fifth Way.

¹² See William Paley, Natural Theology, (1802) (Houston: St. Thomas Press, 1972), pp. 1-2.

¹³ Paley, Natural Theology, pp. 14-15.

¹⁴ See Paley, Natural Theology, pp. 42-43: “There may be also parts of plants and animals…of which in some instances, the operation, in others, the use is unknown. These form different cases; for the operation may be unknown, yet the use be certain. Thus it is with the lungs of animals. It does not, I think, appear, that we are acquainted with the action of the air upon the blood, or in what manner that action is communicated by the lungs; yet we find that a very short suspension of their office destroys the life of the animal. In this case, therefore, we may be said to know the use, nay we experience the necessity, of the organ, though we be ignorant of its operation. … There may possibly also be some few examples of the second class, in which not only the operation is unknown, but in which experiment may seem to prove that the part is not necessary…. This is said to be the case of the spleen; which has been extracted from dogs, without any sensible injury to their vital function.”

¹⁵ See, for example, Jonah Schupback and Graham Oppy's articles in Philosophia Christi on whether Paley's argument is deductive or not: Schupbach, Jonah, “Paley's Inductive Inference to Design: A Response to Graham Oppy”, Philosophia Christi, 7 (2005), pp. 491-502CrossRefGoogle Scholar and Oppy, Graham, “Paley's Argument Revisited: Reply to Schupbach”, Philosophia Christi, 10, 2 (2008), pp. 443-50CrossRefGoogle Scholar.

¹⁶ Paley, Natural Theology, pp. 15-16.

¹⁷ Paley, Natural Theology, p. 9.

¹⁸ Paley, Natural Theology, p. 66.

¹⁹ Paley, Natural Theology, p. 60. See also, ibid., p. 57: “IT is not that every part of an animal or vegetable…is not constructed with a view to its proper end and purpose, according to the laws belonging to, and governing the substance or the action made use of in that part; … but it is because these laws themselves are not in all cases equally understood; or, what amounts to nearly the same thing, are not equally exemplified in more simple processes, and more simple machines; that we lay down the distinction, here proposed, between the mechanical parts and other parts of animals and vegetables.”

²⁰ Paley, Natural Theology, p. 60.

²¹ Paley, Natural Theology, p. 14.

²² See Paley, Natural Theology, p. 15: “To some it may appear a difference sufficient to destroy all similitude between the eye and the telescope, that the one is a perceiving organ, the other an unperceiving instrument. The fact is, that they are both instruments. And, as to the mechanism, at least as to mechanism being employed, and even as to the kind of it, this circumstance varies not the analogy at all.”

²³ For a more exact account of the argument by analogy (which Aristotle calls the argument by example), see Aristotle, Prior Analytics, Bk. II, chap. 24.

²⁴ Summa contra Gentiles, Bk. 3, c. 64 (“non aliter fierent si fierent per artem”).

²⁵ Aristotle, Posterior Analytics, trans. Hugh Tredennick (Cambridge Massachusetts: Harvard University Press, 1976), 100b3-4; I very slightly altered this translation. Aquinas is in agreement with Aristotle on these points; see In Libros Posterior Analyticorum Expositio, ed. Spiazzi, Raymundi M. O.P. (Turin: Marietti, 1964), #595-96Google Scholar: “He [Aristotle] manifests what he said…as to this that the universal is grasped from the experience of singulars. … Therefore, because we grasp knowledge of universals from singulars, he concludes that it is manifest that it is necessary that the first universal principles are known through induction. For in this manner, namely, through the way of induction, sense causes the universal in the soul, insofar as all singulars are carefully regarded.”

²⁶ Another question is: to what extent can the relationship of means to ends be sensed? It seems that chimpanzees that fish for termites sense that this twig is too big to fit the hole and that one is the right size.

²⁷ Perhaps the proposition that things that lack knowledge must be ordered to their ends by an intelligent being is not self-evident to just anyone, but is “self-evident only to the wise;” see Summa Theologiae, I-II 94.2. For a brief discussion of whether the major premise of the second syllogism of Aquinas's Fifth Way is self-evident, see George, Marie I., “On the Occasion of Darwin's Bicentennial: Finally Time to Retire the Fifth Way?”, Proceedings of the American Catholic Philosophical Association, 83 (2009), pp. 216-18Google Scholar.

²⁸ Quaestiones Disputatae de Potentia, q. 1, a. 5.

²⁹ Quaestiones Disputatae de Veritate, q. 5, a. 2.

³⁰ See Paley, Natural Theology, p. 9.

³¹ Feser, “Between Aristotle and William Paley,” p. 743.

³² Feser, “Between Aristotle and William Paley,” p. 742.

³³ I have paraphrased the following passage from Paley: “[W]hen we come to inspect the watch, we perceive (what we could not discover in the stone) that its several parts are framed and put together for a purpose, e.g. that they are so formed and adjusted as to produce motion, and that motion so regulated as to point out the hour of the day. … This mechanism being observed…and understood, the inference, we think, is inevitable…that there must have existed at some time and at some place or other, an artificer…who comprehended its construction and designed its use” (Natural Theology, pp. 2-3)

³⁴ ST I-II, q. 13, a. 2, ad 3.

³⁵ Scriptum super Sententiis, Bk. 3, d. 20, q. 1, a. 1, qc. 3, s.c. 1.

³⁶ Summa contra Gentiles, Bk. 2, c. 45.

³⁷ Ibid., Bk. 3, c. 100.

³⁸ The Vulgate uses the word “artifex” in Ws. 13.1.

³⁹ Feser, “Between Aristotle and William Paley,” p. 742. See also Feser, blog posting, http://edwardfeser.blogspot.com/2011/03/thomism-versus-design-argument.html: “No one denies that both Aquinas and Paley argue for an intelligent cause of the order in the world.  What A-T philosophers (other than George) object to is the way Paley argues for this conclusion (a way which is incompatible with A-T metaphysics) and the anthropomorphic construal of “intelligence” implicit in his position (which is incompatible with classical theism).”

⁴⁰ See Paley, Natural Theology, pp. 1-2.

⁴¹ See Paley, Natural Theology, c. 21 (“The Elements”), p. 280: “When we come to the elements, we take leave of our mechanics; because we come to those things, of the organization of which, if they be organized we are confessedly ignorant.” Paley also notes in the case of the heavenly bodies: “We are destitute of the means of examining the constitution of the heavenly bodies. The very simplicity of their appearance is against them. We see nothing, but bright points, luminous circles, or the phases of spheres reflecting the light which falls upon them. Now we deduce design from relation, aptitude, and correspondence of parts. Some degree therefore of complexity is necessary to render a subject fit for this species of argument” (p. 287).

⁴² This point perhaps deserves further consideration; however, an exhaustive examination of the Fifth Way falls outside my main purpose. An animal is a natural body that does not lack knowledge; however, its vegetative activities go on apart from its knowledge (see De Potentia, q. 1, a. 5), and same for its falling downwards.

⁴³ In Octo Libros de Physico Auditu Commentaria, Bk. 2, lec. 12, #491 (Pirotta edition). See also De Potentia, q. 2, a. 3, ad 5: “Whence the Philosophers were not led to posit the work of nature to be a work of intelligence from the operations which belong to the hot and the cold in virtue of themselves; because those positing natural things to happen from the necessity of the matter were reducing all works of nature also into these [causes]. They were led, however, from those operations for which the power of hot and cold and things of this sort cannot suffice; as from the members in the animal body being ordered in such a way that the nature [of the animal] was preserved” (emphasis added). See also Disputed Question De Anima, a. 10, ad 17. Some object that the Fifth Way does not embrace design since the Fifth Way is concerned with the “governance of things” and not their creation or production. Space does not allow me to fully respond to this objection. I concede it, if governance is understood in the narrow sense which distinguishes it from creation (see De veritate, q. 5 a. 8, ad 2), but not if it is understood in the broad sense, such as is used in regard to divine justice (see ST I, q. 21, a. 1 and ad 3). Footed animals’ living bodies are natural bodies, and during development they regularly produce feet composed in a manner that makes them suitable for walking; thus, the footed animal body is a particular instance of what the first syllogism refers to in general terms. This gives reason us to take governance in the broad sense.

⁴⁴ Feser, “Between Aristotle and William Paley,” p. 723.

⁴⁵ See Feser, “Between Aristotle and William Paley,” p. 723 and p. 723, note 30.

⁴⁶ Paley, Natural Theology, p. 52. That he thinks that his argument concludes with certitude and not with probability can also be seen from his earlier remark in regard to a watch: “Sixthly, he would be surprised to hear, that the mechanism of the watch was no proof of contrivance, only a motive to induce the mind to think so” (ibid., p. 5).

⁴⁷ Paley, Natural Theology, pp. 55-56.

⁴⁸ Paley, Natural Theology, p. 16.

⁴⁹ See Glenn Branch, “Did Paley Anticipate Behe?,” posted on September 17, 2013, http://ncse.com/blog/2013/09/did-paley-anticipate-behe-0015009: “Anyhow, it's not surprising that readers were quick to associate Behe's argument with Paley's. Taking a case practically at random, in 1998, the biochemist Bruce H. Weber wrote, ‘Michael Behe restates in modern biochemical terms William Paley's argument that there is an irreducible functional complexity to living beings that suggests the action of a designer-creator.’”

⁵⁰ See Martin, Christopher, Thomas Aquinas: God and Explanations (Edinburgh: Edinburgh University Press, 1997), p. 182CrossRefGoogle Scholar.

⁵¹ Paley, Natural Theology, 2. See Behe, Michael, Darwin's Black Box (New York: The Free Press, 1996), p. 39Google Scholar: “By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning. An irreducibly complex system cannot be produced directly (that is, by continuously improving the initial function, which continues to work by the same mechanism) by slight, successive modifications of a precursor system….”

⁵² Paley, Natural Theology, p. 2. Note that Paley later observes that things can be more or less well-designed, and this shows that he is not wedded to the idea that there could not be differences in the parts as to shape, size, or ordering in things that are designed to serve a given purpose: “Neither, secondly, would it invalidate our conclusion, that the watch sometimes went wrong, or that it seldom went exactly right. … It is not necessary that a machine be perfect, in order to shew with what design it was made…” (p. 3).

⁵³ Paley, Natural Theology, 8-9.

⁵⁴ See Behe, Darwin's Black Box, pp. 203-204: “If a biological structure can be explained in terms of those natural laws [biological reproduction, mutation, and natural selection], then we cannot conclude that it was designed. Throughout this book, however, I have shown why many biochemical systems cannot be built up by natural selection working on mutations.”

⁵⁵ See Paley, Natural Theology, pp. 1-2.

⁵⁶ Paley's argument is sometimes criticized as being a god-of-the-gaps argument: “Asa Gray...was able to leave behind Paley's view that on the ‘God-of-the-gaps’ is worthy of being recognized in nature” (Bethany Sollederer, “The Darwin-Gray Exchange”, Theology and Science, 8, 4 (November 2010), p. 425). Paley's argument from design, again, is not based in what may turn out to be gaps in our knowledge concerning the ability of natural causes to produce certain effects, but rather on the notion that such causes cannot account for the ordering to an end we observe in the features of living things.

⁵⁷ Hume, Dialogues concerning Natural Religion in Hume, Selections, ed. Hendel, Charles W. (New York: Charles Scribners's Sons, 1927), 330Google Scholar.

⁵⁸ ST I, q. 3, a. 4: “It is necessary, therefore, that that whose being is other from its essence has being caused by another. This is not able to be said of God, for we say that God is the first efficient cause of being. Therefore, it is impossible that in God his being is one thing and his essence another.”

⁵⁹ See ST I, qq. 14, 15, and 22.

⁶⁰ Paley, Natural Theology, pp. 42-43.

⁶¹ Paley, Natural Theology, p. 181.

⁶² Paley himself acknowledges that his argument is compatible with the existence of a Demiurge. However, his design argument of itself does not commit him to asserting the existence of such a being; see Natural Theology, p. 28.

⁶³ Note that the conclusion of the Fifth Way does not offer an immediate answer to the question of “whether the forms of bodies are from angels” (see ST I, q. 65, a. 4), a question similar to whether a demiurge exists. Yet no one would think to fault the Fifth Way for so much; indeed to do so would be to introduce an irrelevant thesis into the discussion.

⁶⁴ A question worth pursuing is whether Paley's argument is more difficult to defend than the Fifth Way is in the face of claims that random variation and natural selection offer a complete explanation of the original of adaptations in organism; see Feser, “Between Aristotle and William Paley,” p. 740. A closely related question is how Paley and Aquinas compare as to their rejection of chance as an explanation for ordering to an end in organisms. Aquinas's argument consists of two syllogisms, and it is the first of the two syllogisms which addresses chance.

⁶⁵ Paley's argument seems to have an advantage over Aquinas's in that it is not clear in the case of non-living natural things that they tend to some good. Aquinas affirms that: “All natural bodies, lacking knowledge, operate in the same mode such that what is obtained is the best.” Yet what is the good that a rock or water tends to? In the case of most organic parts, the good they tend to is apparent; eyes are for the sake of sight which is a good, and hands are for the good of grasping food, etc. Aquinas, taking inspiration from Aristotle, sees the natural motions of the elements to have as their goal places that preserve them, but I fail to see that how this is true (see Commentary of the Physics, Bk. 4, lec. 1, #411-12 (Marietti edition).