Aquinas: Natural Science

Le Commentaire du Traité de l'âme d'Aristote par Thomas d'Aquin est le cinquième des commentaires fondamentaux des oeuvres d'Aristote traduits en langue française. Avec celui des Physiques, de la Métaphysique, de l'Interprétation et des Analytiques, il fonde l'édifice de la philosophie de Thomas d'Aquin et assure les contreforts de sa théologie. Ce traité se présente comme un vaste essai de définition de l'âme et principalement de l'âme humaine, avec en filigrane, une question lancinante : cette âme est-elle immortelle? Si ce (...) traité est l'un des plus courts d'Aristote, et selon ses propres termes, encore à l'état d'ébauche, il est construit avec une rigueur méthodologique qui en fait une sorte de modèle pour toute réflexion philosophique. Thomas propose une explication reconnue comme des plus limpides, et introduit à un livre encore loué deux millénaires plus tard par Hegel, Marx ou Darwin. Comme le reste de l'oeuvre d'Aristote, il connaît aujourd'hui un regain d'intérêt remarquable et le commentaire de Thomas offre un guide très sûr pour son intelligence. (shrink)

Aristotelian commenters have long noted an apparent contradiction between what Aristotle says in Posterior Analytics I.2 and Physics I.1 about how we obtain first principles of a science. At Posterior 71b35–72a6, Aristotle states that what is most universal (καθόλου) is better-known by nature and initially less-known to us, while the particular (καθ’ ἕκαστον) is initially better-known to us, but less-known by nature. At Physics 184a21-30, however, Aristotle states that we move from what is better-known to us, which is universal (καθόλου), (...) to what is better-known absolutely, which is particular (καθ’ ἕκαστον). This paper turns to two of Aristotle’s most notable medieval commentators—Albertus Magnus and Thomas Aquinas—to resolve this apparent contradiction. The key to Thomas and Albert’s solutions, we will argue, is a twofold distinction between a sense-perceptive and scientific universal, and the particulars as sensed individuals and as differentiating attributes. Our Synthetic treatment of these distinctions contributes to the ongoing scholarly effort to understand the Stagyrite’s complex theory of knowledge. (shrink)

This paper offers an analysis of work on human development in evolutionary anthropology from a Thomist perspective. I show that both fields view care for others as fundamental to human nature and interpret cooperative breeding as expression of the virtue of charity. I begin with an analysis of different approaches to the relationship between evolutionary anthropology and moral theory. I argue that ethical naturalism is the approach best suited to interdisciplinary dialogue, since it holds that natural facts are useful for (...) moral theory but do not encompass it. This forms the basis for a Thomist analysis of some key features of human evolution including bipedalism, higher encephalisation and extended childhood. In each case I explain how these parts of our nature contributed to the evolution of modern humans, and how each is reliant upon communal care. Finally, I offer three observations on these facts from a Thomist perspective. Firstly, that a good human life necessarily involves caring for others and being cared for ourselves. Secondly, that this is exemplified in the virtue of charity, which is the ground of all virtue. Finally, that the need for such care shows that human flourishing cannot be attained without divine aid. (shrink)

The metaphysics underlying differences in degree of qualitative intensity was widely debated in the medieval period. Medieval Aristotelians agreed that subjects possess qualities in virtue of inherent accidental forms. Yet, there was considerable disagreement about what happens at the level of form when a quality increases or decreases in its intensity. For instance, what happens when a pot of water on the stove gets hotter? Is the water’s previous form of heat replaced by a new one, or does the same (...) form of heat persist? Does the form of heat itself undergo a change, or does only the water undergo a change? While there have been several important studies on the medieval debate about the “intension and remission of forms,” little attention has been paid to Thomas Aquinas’s intriguing theory. Aquinas claims that a subject’s quality increases in intensity in virtue of the subject “participating” more perfectly in an invariable form. This paper examines Aquinas’s conception of the participation relationship between a substance and its accidental forms; and his metaphysical analysis of changes of intensification. (shrink)

Several medieval commentators on De caelo II, 7 investigate the question of whether local motion causes heat. I analyse the theories of Averroes, Albert the Great, Thomas Aquinas, Peter of Auvergne, John of Jandun, John Buridan and Nicole Oresme and two anonymous theories. Although all of these authors agree that local motion generates heat, each of them presents his own explanation of the heating effect of motion. Averroes, Thomas Aquinas, John of Jandun and John Buridan argue that motion is the (...) per se cause of heat. Their explanations of the heating effect of motion are based on metaphysical considerations such as the relation between a subject and its characteristics or perfections and the causal order in a genus. Albert the Great, Peter of Auvergne, Nicole Oresme and the anonymous commentators, on the contrary, defend the thesis that motion is the accidental cause of heat. Their explanations refer to physical processes caused by motion. (shrink)

Prime Matter Pluralism (PMP) states that while the prime matter of all terrestrial bodies is the same, there is a unique prime matter for each celestial body. Prime matters are distinct in virtue of being in potentiality to different forms. Steven Baldner argues that although Thomas Aquinas endorsed PMP in Summa theologiae I, he ultimately rejected it in his De caelo commentary and De substantiis separatis. Besides exegetical evidence for this claim, Baldner presents a philosophical objection to PMP: according to (...) PMP, distinct prime matters are restricted in their respective potentialities; such restriction requires form, however; therefore, prime matter is not pure potentiality. Since prime matter is pure potentiality, PMP is false. Pace Baldner, I argue that Aquinas endorses PMP as heartily in the later works as in STh I. Moreover, he resisted substantially the same objection to PMP as Baldner’s several times. In particular, Aquinas repeatedly rejected the claim that the restriction of prime matter’s potentiality requires form. In that case, when Aquinas calls prime matter “pure potentiality,” he means that it is formless of itself, not that it is in potentiality to any form whatsoever. (shrink)

In this paper I discuss the role of non-humans in Aquinas’ account of moral learning. I intend to show that the entire created order can play an important role in demonstrating to us the life of virtue, and argue that non-human exemplars offer important advantages to the moral learner. I begin by addressing apparent problems with this approach, founded on the observation that human virtue, for Aquinas, is unique to humans. I resolve these by showing that Aquinas’ approach to exemplars (...) is fundamentally analogical, meaning that exemplars point beyond themselves and need not necessarily live the good life to which they direct learners. I show that this means that Aquinas can use non-humans as moral exemplars and offer examples of him doing just that. Finally, I offer an assessment of the benefits of this approach. Among other things, it offers ethicists new ways to focus on particular virtues and provides a plausible way to include non-humans in the moral realm. (shrink)

Prime Matter Pluralism (PMP) states that while the prime matter of all terrestrial bodies is the same, there is a unique prime matter for each celestial body. Prime matters are distinct in virtue of being in potentiality to different forms. Steven Baldner argues that although Thomas Aquinas endorsed PMP in Summa theologiae I, he ultimately rejected it in his De caelo commentary and De substantiis separatis. Besides exegetical evidence for this claim, Baldner presents a philosophical objection to PMP: according to (...) PMP, distinct prime matters are restricted in their respective potentialities; such restriction requires form, however; therefore, prime matter is not pure potentiality. Since prime matter is pure potentiality, PMP is false. Pace Baldner, I argue that Aquinas endorses PMP as heartily in the later works as in STh I. Moreover, he resisted substantially the same objection to PMP as Baldner’s several times. In particular, Aquinas repeatedly rejected the claim that the restriction of prime matter’s potentiality requires form. In that case, when Aquinas calls prime matter “pure potentiality,” he means that it is formless of itself, not that it is in potentiality to any form whatsoever. (shrink)

Science-engaged theology has emerged as a new way of conducting research within the vast field of science and religion, with the aim of, at least in one way of understanding it today, solving theological puzzles. In this article we suggest that an analysis of the diversity of approaches in which thirteenth-century philosopher and theologian Thomas Aquinas engaged theological questions with the best knowledge of the natural world available at the time allows twenty-first century science-engaged theologians to move forward the discussion (...) about the different ways of engaging theology with the contemporary natural sciences. (shrink)

In this paper I discuss the role of non-humans in Aquinas’ account of moral learning. I intend to show that the entire created order can play an important role in demonstrating to us the life of virtue, and argue that non-human exemplars offer important advantages to the moral learner. I begin by addressing apparent problems with this approach, founded on the observation that human virtue, for Aquinas, is unique to humans. I resolve these by showing that Aquinas’ approach to exemplars (...) is fundamentally analogical, meaning that exemplars point beyond themselves and need not necessarily live the good life to which they direct learners. I show that this means that Aquinas can use non-humans as moral exemplars and offer examples of him doing just that. Finally, I offer an assessment of the benefits of this approach. Among other things, it offers ethicists new ways to focus on particular virtues and provides a plausible way to include non-humans in the moral realm. (shrink)