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Monday, September 24, 2012

0244: Aquinas’ Five Ways and Aristotle (VII)

Entry 0244: Aquinas’ Five Ways and Aristotle (VII)

Concerning Aristotle’s influence on the formulation of the Fifth Way, in his The Philosophical Theology of St. Thomas Aquinas, ([Leiden, The Netherlands: E. J. Brill, 1990], 121-125) Leo Elders writes:

“The teleological argument is that proof of God’s existence which is most widely found in religious and philosophical tradition. The reason is that it is obvious to man that order does not come from nothing but requires someone who arranges things.

“In the prologue to the Lectura super Evang. Ioannis St. Thomas calls this the most efficacious way.

“Aristotle gives a version of this proof of God in De philosophia (Fr. 10 R). And in Metaph. XII 10, 1076 a 3 Aristotle attributes to Homer the thesis that there must be one principle which governs the cosmos.

St. Thomas agrees with Aristotle that this teleological organization shows most in animal life (In II Phys., I.13, n.259).

“Against the objection that it is impossible to speak of finality in inanimate bodies, St. Thomas maintains that natural things without knowledge act for an end, because they always act in the same way so as to obtain the best result (‘id quod est optimum’).

“What does Aquinas mean by his statement that these natural things are always or almost always acting in the same way and reach what is best? When we read this text against the background of the commentary on Aristotle’s Physics II, lesson 13 which explicitly studies this question, we notice that to act for an end is distinguished from chance events. What happens by chance is not directed towards a certain purpose. The classic example is that of a tile falling from a roof which hits a pedestrian who happens to be passing.

“It is impossible that things which happen always or in most cases in the same way, come about by chance. (The wording of the first lines of the Fifth Way is very close to Aristotle’s text [Phys. II, c.8] and that of St. Thomas commentary [ibid., n.256]). The reason is that in chance events there is no intended connection between an action and the result obtained. Therefore this result comes about in a capricious manner.

“In the activity of natural things where there is a final term, there is an intended connection between the action itself and its result.

St. Thomas explains this in his already quoted commentary: when something is done naturally in a certain way, it has a natural disposition and aptitude (‘aptum natum est’) to be done in this way (In II Phys., n.257). This is precisely what Aristotle writes himself: ‘and as they are by nature such as to be, so they are done, if there is no impediment’ (Phys., 199 a 10 transl. by W. Charlton).

“What Aristotle writes is obvious: every year in spring the sun climbs higher in the ecliptic, it warms the atmosphere and the higher temperature melts the snow; the chemical elements react with one another according to a set affinity; in the course of the seasons of the year plants act always or almost always in a regular pattern to reach certain ends. They do so according to their natural aptitude. Nature has fitted them out in such a way that these activities follow conveniently and easily. (See In II Phys., I,12, n.252.)”

Monday, September 17, 2012

0243: Aquinas’ Five Ways and Aristotle (VI)

Entry 0243: Aquinas’ Five Ways and Aristotle (VI)

Regarding the sources of the Fourth Way, Leo Elders pointed out that “it is remarkable that both in the Summa contra gentiles, I, 13 and in the Summa theologiae, I, 2, 3 as well as in the Quaestio disputata de potentia, 3, 5, Aquinas refers to Aristotle. The texts of the Corpus quoted are Metaph. II 993 b 24 f. and IV 1004 b 2 ff (there are degrees in falsehood, therefore also in truth). The principle formulated by Aristotle has already been discussed in our analysis.”

In the analysis, Elders asks “How can we proceed from the existence of limited perfections to that of an unlimited being?”

And he answers that “St. Thomas has taken over from Aristotle or rather from the Corpus Aristotelicum the principle: ‘That which gives other things a certain form or perfection has itself this perfection to the highest degree.’ However, Aquinas uses the maxim in a different way and states that where a perfection is found according to more or less there must be something which has it most.”

“Although the doctrine of participation is hardly Aristotelian,” Elders continues, “Aristotle nevertheless admits that at the level of efficient causality there is a first and a maximum with regard to qualities. He uses the example of fire as an illustration.”

The footnote attached to this affirmation reads as follows: “Metaph. II (a) 1, 993 b 25: fire is hottest and so it is to other things the cause of their heat. Aristotle presents an argument from the degrees of being in the De philosophia, fr. 16. See De ideis, fr. 3. One may also compare Met. 1055a 3 ff.”

Elders then adds, “Above all Aristotle teaches the unity of being, which to St. Thomas is of paramount importance: the transcendentals coalesce in the unity of the concrete thing and do not constitute juxtaposed distinct formal realities.”

Elders further explains that “The transcendentals are modes of being rendering explicit what is already contained in things. Being shows itself in the perfections it exhibits. For this reason St. Thomas can pass from the transcendental concepts to a conclusion about being. He does so with the help of an argument borrowed from Metaphysics II 1: ‘Things which are truest, are also most being.’ In this chapter Aristotle shows that the highest things, viz. principles and causes, are truest because they are the ground of our knowledge and certitude. St. Thomas changes the order somewhat and argues from truth to being. The argument is valid, for ‘truest’ is that being which also communicates its truth to others. This is what causes do.”

Finally, Elders points out that “In De substantiis separatis (chapter 3) St. Thomas describes Plato’s doctrine of participation and explains to what extent it agrees with Aristotle views.” (1)


(1) Leo J. Elders, The Philosophical Theology of St. Thomas Aquinas, (Leiden, The Netherlands: E. J. Brill, 1990), 113-119.

Monday, September 10, 2012

0242: Aquinas’ Five Ways and Aristotle (V)

Entry 0242: Aquinas’ Five Ways and Aristotle (V)

Regarding the Third Way, Leo Elders affirms that for Aquinas the possibility of being and of not being belongs to things on account of their matter. And more specifically regarding the influence of Aristotle, Elders affirms that “The ‘it is impossible that these things always exist’ is a principle given by Aristotle in the De caelo 1 cc. 10-12 and accepted by St. Thomas who even explains it in a subsequent line: ‘for that which can not-be, at some point is not.’ This statement is the central point of the argument: a corruptible thing which would never cease to exist, would have the possibility of not being corrupted, while at the same time it is corruptible. But this is impossible. (See In I De caelo, 1.29, n.283 and 1.26, n.257.)” (1)

Later Elders explains that regarding the influence of Aristotle on the Third Way, “some have pointed out to Metaph. XII 6, 1071 b 22-27 as the source of the argument: What is possible, does not have existence of itself but depends on something in act; of itself a possible being remains in potency; from the point of view of possibility alone at some time nothing is.” And then Elders adds that “More recently scholars have drawn attention to the De caelo I 12, where the statement is found: ‘What can not be, at a certain time is not.’ With this insight Aristotle provided an essential element for the argument as we find it in the Summa theologiae.” (2)


(1) Leo J. Elders, The Philosophical Theology of St. Thomas Aquinas, (Leiden, The Netherlands: E. J. Brill, 1990), 102-103.

(2) Ibid., 107.

Monday, September 3, 2012

0241: Aquinas’ Five Ways and Aristotle (IV)

Entry 0241: Aquinas’ Five Ways and Aristotle (IV)

On the sources of Aquinas’ Second Way of demonstrating the existence of God, Leo J. Elders remarks that

“In Summa contra gentiles I, 13 Aquinas seems to ascribe the argument to Aristotle. However, upon closer inspection the text does not say more than that Aristotle shows that in a series of efficient causes infinite regress is not possible and that, therefore, there must be a first.”

Elders then explains that “Aristotle's text is found in Metaph. II (a) 2, 994 a 1ff., where he [Aristotle] sets forth the principle that in a series of causes, whether material, formal, efficient, or final, there must be a first, but it is not used as a demonstration of God's existence. Aristotle could hardly have done so because God is neither a first material nor a first formal cause. In his commentary on the text Aquinas refrains from reading a demonstration of God's existence into these lines.”

Finally, Elders concludes by saying that “Van Steenberghen's statement [in Le probleme de l'existence de Dieu dans les √©crits de S. Thomas d'Aquin, Louvain-la-Neuve, 1980, p. 187] that the Second Way is entirely taken from Aristotle must be qualified.” (1)


(1) Leo J. Elders, The Philosophical Theology of St. Thomas Aquinas, (Leiden, The Netherlands: E. J. Brill, 1990), 100.