The Relation-Theory of Mental Acts

The relation-theory of mental acts proposes that a mental act is a kind of relative entity founded upon the mind and directed at the object of perception or thought. While most medieval philosophers recognized that there is something importantly relational about thought, they nevertheless rejected the view that mental acts are wholly relations. Rather, the dominant view was that a mental act is either in whole or part an Aristotelian quality added to the mind upon which such a relation to the object can be founded. This paper examines Durand of St.-Pourçain’s defense of the relation-theory of mental acts against two objections raised against it: the first from John Duns Scotus, among others, and the second from an anonymous Thomist and Adam Wodeham

Scotus versus Aquinas on Instrumental Causality

The medieval notion of instrumental cause is not limited to what we call today “instruments” or “tools.” It extends way beyond the realm of technology and includes natural entities, for instance, the accidents by which a substance acts on another substance, sensible species in the air acting on a visual faculty, sacraments, bodily organs, and sometimes creatures with respect to God’s action. In all these cases, instrumental causes, like secondary causes in general, are subordinated to a principal cause and contribute to its action and effects. However, the manner in which they do so makes them different from regular secondary causes, and the specifics are not easy to pinpoint. At the occasion of discussions about creation ex nihilo and sacraments, John Duns Scotus challenges Thomas Aquinas’s theory of instrumental causality. Whereas Aquinas does not strongly distinguish between artifacts and natural agents, and postulates a complex superposition of layers of causation, Scotus offers a novel view that clearly separates artificial instrumentality and natural instrumentality, and in both cases explains causation with great economy. Scotus’s in-depth discussion has far-reaching implications. It completely transforms the understanding of instrumental causality in general.

Accidental Forms as Metaphysical Parts of Material Substances in Aquinas’s Ontology

Following in the hylomorphic tradition of Aristotle, Thomas Aquinas holds that all material substances are composed of matter and form. Like Aristotle, Aquinas also recognizes two different types of forms that material substances can be said to possess: substantial forms and accidental forms. Of which form or forms, then, are material substances composed? This paper explores two competing models of Aquinas’s ontology of material substances, which diverge on precisely this issue. According to what the author refers to as the “Standard Model,” Aquinas’s view is that a material substance is composed of prime matter and substantial form. According to the “Expanded Model,” Aquinas’s view is that a material substance is composed of prime matter, substantial form, and all of its accidental forms. After outlining the main claims of each of the two competing models and considering two arguments in favor of the Standard Model, the author offers two arguments in favor of the Expanded Model. He argues that, given the way in which Aquinas argues for God’s simplicity in question three of the Prima pars, and the way in which he consistently describes the difference between an essence and a suppositum, or individual substance, throughout his works, there is good reason to believe that Aquinas thinks that the accidental forms of a material substance are included among its metaphysical parts.

Only God Can Make a Tree

sProblems about the nature of integral parts and wholes were central to twelfth-century discussions of the individuation and persistence over time of both substances and artifacts. This paper examines in detail Abaelard’s contribution to these discussions arguing that Abaelard proposes a solution to these problems which preserves our common sense intuitions about identity over time. In Abaelard’s work we find an explicit solution to the problem of the identity over time of living things which appeals to the persistence of the vegetative soul through the loss or addition of corporeal matter. In work from the school of the Montani we apparently also have an account of Abaelard’s solution to the problem of the identity over time of artifacts which distinguishes between the role of a part in an integral whole and the material which plays that role such that the role persists when the matter is replaced.

Walter Chatton’s Rejection of Final Causality

The paper examines Walter Chatton’s rejection of final causality. At the core of Chatton’s theory lies the claim that there are four kinds of cause (material, formal, efficient, and final), but only three kinds of causality, because final causality should in a sense be reduced to efficient causality. The author begins by situating Chatton’s theory in the context of the fourteenth-century discussions concerning the problematic status of ends as causes. After that, the paper reconstructs Chatton’s rejection of the opinio communis of his time, according to which both final causes and final causality must be posited. The author claims that Chatton’s objections employ three main arguments, based on (1) ontological parsimony, (2) possible non-existence of ends, and (3) the efficient character of love and desire. Then, Chatton’s own theory is presented. The author’s exposition is focused on Chatton’s thesis that final causes are said to be causes only in a metaphorical sense. The final part of the article examines William of Ockham’s reaction to Chatton’s theory. Arguing against Chatton’s teleology, Ockham wants to prove that we have good reasons to retain both final causes (as real causes) and final causality.

Aquinas on the Intension and Remission of Accidental Forms

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.

Aquinas on the Sources of Wrongdoing

Colleen McCluskey begins Thomas Aquinas on Moral Wrongdoing with an overview of Aquinas’s account of human nature and his theory of human action. She discusses the powers of the soul, including the sensory appetite and its passions, the intellect, and the will. Crucially, she devotes considerable attention to the ways in which the passions can affect the intellect’s judgment and, thereby, the will. She then explores Aquinas’s account of the ontological status of evil as a privation, arguing that criticisms of the privation theory can be met, though the theory is not enough by itself to acquit God of responsibility for the existence of evil. The centerpiece of Thomas Aquinas on Wrongdoing is a careful exploration of Aquinas’s understanding of the three sources of moral wrongdoing: defects in the intellect (sins from ignorance), defects in the sensory appetite (sins from passion), and defects in the will (sins ex certa malitia, in which an agent chooses a lesser good, not in ignorance or under the influence of a passion, but knowingly). Finally, McCluskey examines vices, which are firmly rooted dispositions, acquired by repeated action, that prompt particular acts of wrongdoing. She provides a helpful overview of Aquinas’s treatment of the vices both in ST II-II, where the vices are discussed in relation to the virtues to which they are opposed, and in the contemporaneous De malo, questions 9–15, in which Gregory the Great’s list of seven capital vices provides the structuring principle.

“Not So Ridiculous”

This chapter explicates a distinctive argument that Avicenna offers for the existence of nature as a causal power in bodies. In doing that, the author shows the argument has two main targets: the Aristotelian tradition on the hand, who thought that the existence of nature, as an intrinsic principle of movement, was self-evident, and the Ash ͑arite occasionalist theological tradition on the other, who were anti-realists about all creaturely efficacious power, locating all efficacy instead in an extrinsic transcendent agent. The argument draws on two key premises: a regularity of events thesis and a version of the principle of sufficient reason (PSR). Based on these two premises, Avicenna offers a response to the issue in a way that attempts to preserve something from both traditions. For it allows, with the Ash ͑aris, the causal involvement of a transcendent being in the production of some effect or range of effects from some body; and yet still maintains, against them and with the Aristotelians, that the effect must occur in virtue of some property of that body, where the property in question makes a real causal contribution to the effect’s occurrence. This amounts to a properly Avicennian account.