The Validity of Aquinas' Third Way (original) (raw)
Related papers
1998
The Third Way is the most interesting and insightful of Aquinas' five arguments for the existence of God, even though it is invalid and has some false premises. With the help of a somewhat weak modal logic, however, the Third Way can be transformed into a argument which is certainly valid and plausibly sound. Much of what Aquinas asserted in the Third Way is possibly true even if it is not actually true. Instead of assuming, for example, that things which are contingent fail to exist at some time, we need only assume that contingent things possibly fail to exist at some time. Likewise, we can replace the assumption that if all things fail to exist at some time then there is a time when nothing exists, with the corresponding assumption that if all things possibly fail to exist at some time then possibly there is a time when nothing exists. These and other similar replacements suffice to produce a cogent cosmological argument. Aquinas' Third Way is a cosmological argument for ...
Reconsidering the Necessary Beings of Aquinas's Third Way
European Journal for Philosophy of Religion, 2012
Surprisingly few articles have focused on Aquinas’s particular conception of necessary beings in the Third Way, and many scholars have espoused inaccurate or incomplete views of that conception. My aim in this paper is both to offer a corrective to some of those views and, more importantly, to provide compelling answers to the following two questions about the necessary beings of the Third Way. First, how exactly does Aquinas conceive of these necessary beings? Second, what does Aquinas seek to accomplish (and what does he accomplish) in the third stage of the Third Way? In answering these questions, I challenge prominent contemporary understandings of the necessary beings of the Third Way.
From Aristotle's Four Causes to Aquinas' Ultimate Causes of Being: Modern Interpretations
In the concluding chapter of his The Metaphysics of Being of St. Thomas Aquinas in a Historical Perspective, Leo Elders deals with Aristotle's four causes and determines that the study of material causality has no place at all in Thomistic metaphysics. 1 He allows, though, that in metaphysics there are forms of causality that are analogous to material causality: the potentiality of substance with regard to its accidents, of a faculty with regard to its action, and of essence with regard to being. 2 This insight, in my opinion, needs to be pursued further, and there is a need to distinguish more precisely physical causality and metaphysical causality in both Aristotle and Thomas Aquinas. The analogical nature of the four causes and Aristotle's distinction between causality in the Physics and causality in the Metaphysics has been studied extensively by Enrico Berti in Aristotele: Dalla dialettica alla filosofia prima (1977) 3 . After summarizing some of Berti's conclusions, we can proceed to Aquinas' metaphysical thought on causality, _____________ 1 See L. ELDERS, The Metaphysics of Being of St. Thomas Aquinas in a Historical Perspective, E.J. Brill, Leiden 1993, 293. 2 Ibid. 3 It is one of the few treatises that attempts a global consideration of Aristotelian causality. _____________ 22 J. MITCHELL, "The Method of resolutio and the Structure of the Five Ways", Alpha Omega 15 (2012), 339-380. 23 J. A. AERTSEN, Nature and Creature: Thomas Aquinas's Way of Thought, E.J. Brill, Leiden 1988, 92-93. 24 J. AERTSEN, Nature and Creature, 112. 25 THOMAS AQUINAS, De substantiis separatis, ch. 9, n. 95.
Aquinas on the Eternality and Necessity of the World
In this note, we present a new observation of relevance to Aquinas’s third way. Scholars have noted that Aquinas recognizes the existence of a multiplicity of necessary beings, but it has not been recognized that Aquinas’s views concerning the eternality of the world commit him to the epistemic possibility that the world itself is a necessary being. We explain how Aquinas is committed to this possibility and explore its bearing on the success or failure of the third way as a demonstration of God’s existence.
Beyond a Dichotomy. Aquinas’s Theory of Natural Law as a Form of Autonomous Theonomy
Moral Heteronomy. History, Proposals, Reasons, Arguments, special issue of «Dialegesthai. Rivista telematica di filosofia» 19 (2017). https://mondodomani.org/dialegesthai/msv01.htm
Due to his theory of natural law, it is easy to take Thomas Aquinas, in a simplistic reading, as the champion of moral heteronomy, as Kant is that of moral autonomy. If, following Kant, we take as autonomous only a system that justifies moral duty by means of reasons internal to the transcendental structure of the practical agency – i.e. a system that roots morality in maxims that can be deemed universal, and makes no reference to the individual's particular contingent experience (ethical formalism) – there is obviously no way to assume the presence of an autonomous reason in Aquinas' thought. However, if we take a slightly broader account of autonomy than Kant's, as the capacity to deliberate and to give oneself the moral law 1 , rather than merely heeding the injunctions of others, we can claim Aquinas' practical reason not to be heteronomous, since it states the validity of the precepts of natural law by itself. The thesis of my paper is that there are at least two main strategies to foster a non-heteronomous reading of Aquinas's theory of natural law and practical reason. The first, that I consider a weaker strategy, amounts to a " evolutionary " reading of his moral theory, aimed at showing that most of the heteronomous claims we can find in it belong to a juvenile period of his work, characterized (as we will see in a moment) by a philosophical and theological frame, influenced by St Augustine and St Anselm, focused on the idea of participation in the divine rectitude. However, according to several scholars, Aquinas' latter works are based on a significantly different paradigm, which emphasizes Aristotelian practical reason, taken in its autonomous power of deliberation and command. The second strategy is quite stronger. It is aimed at criticizing those who read mature Aquinas as a proponent of moral heteronomy, and thus it consists in deepening the very concepts of moral autonomy and heteronomy, as well as those of practical reason and natural law, so to show the intrinsic possibility of an autonomous reading of Aquinas's major works. To develop such an attempt, I will hark back to a very influential interpretation, namely, that proposed by the Swiss philosopher and theologian Martin Rhonheimer. According to his reading, Thomistic moral law is called " natural " not insofar as it mirrors an external natural order, but as it emerges from a reason which is integral part of human nature 2. Thus, the theory of natural law is to be seen, according to Rhonheimer, as a theory of practical reason that leaves large room to autonomy and to the non-deductive character of moral experience. a. Questioning the Priority of Synderesis In the present section, I shall outline a brief sketch of the first strategy, namely, that of following Aquinas' path from the paradigm centered on the priority of synderesis (the intellectual knowledge of the first practical principles) to a much more complex account of the interplay between practical reason, virtues and first principles of the natural law. As I have anticipated, natural law is often 1 As it should be evident from this definition of autonomy, I am among those who think it possible to take Kant as a kind of moral realist, rather than espousing a constructivist reading of his moral thought. 2 Cf. Rhonheimer (2001), p. 16.
“Back to Nature in Aquinas.” Medieval Philosophy and Theology 5.2 (1996) 205-243.
Perhaps the most famous achievement of Thomas Aquinas lies in his robust conception of nature and the natural world in the face of a n uncompromising theology of grace and divine operation. As is well known, the Aristotelian conception of nature enables Aquinas to steer clear of both occasionalism and naturalism and to affirm the reality of secondary causes in the natural world.1 Nevertheless, is nature itself to be understood as a secondary cause of cosmic events? A recent and prevalent answer is that Aquinas correctly understood that nature in Aristotle is not an efficient cause but a spontaneous source of regular, 'agentless' or 'causeless' changes in the mineral, vegetative, and animal world.2 This position, in my view,
According to the highly controversial “Principle of Alternative Possibilities,” an agent is morally responsible for an action only if he could have done otherwise. In this paper, I will investigate whether Aquinas accepts this principle. I will begin by arguing that if one grants Aquinas’s theory of human action, Frankfurt-style counter-examples do not succeed. For this reason, it is necessary to investigate various texts in order to discover how Aquinas views this principle. Although he does not explicitly discuss it, he does discuss an axiom (taken from Augustine) that is similar to this principle in various ways. I eventually conclude that, even if Aquinas would reject a strict understanding of PAP, he would only demand a relatively common modification of it.
REVISTA PORTUGUESA DE FILOSOFIA, 2023
According to both Jaakko Hintikka and Simo Knuuttila, Aquinas' third way to demonstrate that God exists presupposes the acceptance of the principle of plenitude, i.e., of the claim that all possibilities are realized at some time. Aquinas, however, maintained elsewhere that not all possibilities are always realized, and the coherence of his philosophical project may be called into question if one were to accept Hintikka's and Knuuttila's reading of the third way. In this paper, I argue that it is difficult to present the third way without invoking the principle of plenitude in Hintikka's formulation. The corollary of this claim is that third way cannot be a demonstration within the philosophical system outlined by Aquinas, despite his claim to the contrary. Against the backdrop of this exegetical discussion, it is possible to rephrase Aquinas' third way as a probabilistic argument that shows that God's existence is highly likely, although not necessarily proven.
No Cause, No Credo Aristotelian Realist Philosophy of Nature as Preambula Fidei
Reality, Issue 1, Vol. 2, Spring 2022, 2022
This study presents St. Thomas Aquinas' groundbreaking treatment of the relation between God as Creator and nature through the Aristotelian model of natural causation and the distinction between essentia and esse contra occasionalist conceptions of creation. By clearly distinguishing primary (divine) and secondary (natural) orders of causation, the Angelic Doctor champions Divine omnipotence while preserving the causal integrity of nature at one and the same time. His position on the relation of divine and natural causation in nature is formulated, in part, as a response to the occasionalist doctrine, denying natural causation. While Thomas shows that denying natural causation would actually vitiate divine omnipotence, this study extends his argument showing Aristotelian causation (secondary cause) is a necessary condition-i.e., one of the preambula fidei-for the Christian belief that God is the all-powerful creator of the natural world. This presentation and extension of St. Thomas Aquinas' critique of occasionalism is needed given a continuing trend among Anglo-American Analytic and Humean Christian philosophers to deny natural causation and hold that God is the only cause.