Prolegomena It is fitting to begin this book on intuitionistic type theory by putting the subject matter into perspective. The purpose of this chapter is to ...

There is a long tradition in Western philosophical theology of conceiving God as ‘a being’. It dates back to the Hellenistic period, more particularly to the conjunction of Greek philosophy and the Hebrew religion in Alexandria with Philo, and it became orthodox in the Christian tradition through Augustine. In our time most aspects of this religious tradition have been subjected to a salutary re-examination, but in this the concept of God as ‘a being’ has been relatively neglected. After such a (...) long acceptance of so fundamental a doctrine, it is liable largely to have sunk to the status of a presupposition, entailing a loss of intellectual awareness of what precisely it implies. Even where the Augustinian philosophical argument upon which this concept is based is recognized, as it has been in the long Neoplatonic tradition, it has come to appear as essentially self-evident and thus has not been subjected to fundamental critical examination. Significant of this is that even where the personalistic conception of God has been abandoned, e.g. by the idealist philosophy of the Absolute, the conception nevertheless persists of God as ‘a being’. (shrink)

Good chefs know the importance of maintaining sharp knives in the kitchen. What’s their secret? A well-worn Taoist allegory offers some advice. The king asks about his butcher’s impressive knifework. “Ordinary butchers,” he replied “hack their way through the animal. Thus their knife always needs sharpening. My father taught me the Taoist way. I merely lay the knife by the natural openings and let it find its own way through. Thus it never needs sharpening” (Kahn 1995, vii; see also Watson (...) 2003, 46). Plato famously employed this image as an analogy for the reality of his Forms (Phaedrus, 265e). Just like an animal, the world comes pre-divided for us. Ideally, our best theories will be those which “carve nature at its joints”. While Plato employed the “carving” metaphor to convey his views about the reality of his celebrated Forms, its most common contemporary use involves the success of science -- particularly, its success in identifying distinct kinds of things. Scientists often report discovering new kinds of things -- a new species of mammal or novel kind of fundamental particle, for example -- or uncovering more information about already familiar kinds. Moreover, we often notice considerable overlap in different approaches to classification. As Ernst Mayr put it: No naturalist would question the reality of the species he may find in his garden, whether it is a catbird, chickadee, robin, or starling. And the same is true for trees or flowering plants. Species at a given locality are almost invariably separated from each other by a distinct gap. Nothing convinced me so fully of the reality of species as the observation . . . that the Stone Age natives in the mountains of New Guinea recognize as species exactly the same entities of nature as a western scientist. (Mayr 1987, 146) Such agreement is certainly suggestive. It suggests that taxonomies are discoveries rather than mere inventions. Couple this with their utility in scientific inference and explanation and we have compelling reason for accepting the objective, independent reality of many different natural kinds of things.. (shrink)

In this paper I argue that both defence and criticism of the claim that humans act ‘under the guise of the good’ neglects the metaphysical roots of the theory. I begin with an overview of the theory and its modern commentators, with critics noting the apparent possibility of acting against the good, and supporters claiming that such actions are instances of error. These debates reduce the ‘guise of the good’ to a claim about intention and moral action, and in so (...) doing have become divorced from the theory's roots in classical and medieval philosophy. Aristotle and Aquinas’ ‘guise of the good’ is primarily a metaphysical claim resting on the equivalence between actuality and goodness, from which conclusions about moral action are derived. I show the reasoning behind their theory and how it forms the basis for the claims about intention and action at the centre of the modern debate. Finally, I argue that the absence of its original foundation is apparent in recent attacks on the ‘guise of the good’. It is unsurprising that modern action theory and ethics have not always been able to comfortably accommodate the ‘guise of the good’; they are only telling half of the story. (shrink)

Divine simplicity is central to Thomas Aquinas’s philosophy of God. Most important for Aquinas is his view that God’s existence (esse) is identical to God’s essence; for everything other than God, there is a distinction between existence and essence. However, recent developments in analytic philosophy about the nature of existence threaten to undermine what Aquinas thought regarding divine simplicity. In the first chapter of this dissertation, I trace Aquinas’s thinking on divine simplicity through the various texts he wrote regarding the (...) matter. I establish that it is crucial for Aquinas that God is identical to his existence. But, is it even coherent to talk about “a thing’s existence?” In Chapter Two I summarize the arguments of C.J.F. Williams that existence is not a real property that individuals have and that predicating the word “exists” after the name of an individual produces linguistic gibberish. After considering, and rejecting, in Chapter Three attempts by some philosophers to refute Williams’s arguments, I turn, in Chapter Four, to a more detailed account of what Aquinas means by esse, the Latin word often rendered in English as “existence.” The conclusion that I come to is that Aquinas does not mean by esse what contemporary philosophers have usually meant by “existence.” Rather, he understands esse to be the act by which anything can be anything at all, instead of there being nothing whatsoever. In the final chapter, I turn to implications of this for Aquinas’s views of divine simplicity, showing that rather than being incoherent, Aquinas’s thinking on esse points toward the unfathomable mystery that is God. (shrink)

Plenitude, roughly, the thesis that for any non-empty region of spacetime there is a material object that is exactly located at that region, is often thought to be part and parcel of the standard Lewisian package in the metaphysics of persistence. While the wedding of plentitude and Lewisian four-dimensionalism is a natural one indeed, there are a hand-full of dissenters who argue against the notion that Lewisian four-dimensionalism has exclusive rights to plentitude. These ‘promiscuous’ three-dimensionalists argue that a temporalized version (...) of plenitude is entirely compatible with a three-dimensional ontology of enduring entities. While few would deny the coherence of such a position, and much work has been done by its proponents to appease critics, there has been surprisingly little by way of exploring the various forms such an ontology might take as well as the potential advantages of one plenitudinous three-dimensional ontology over another. Here I develop a novel form of plenitudinous three-dimensionalism, what John Hawthorne (Metaphysical essays, 2006a, b) has called “Neo-Aristotelian Plenitude,” and argue that if one is inclined to endorse an abundant three-dimensional ontology, one is wise to opt for a plenitude of accidental unities. (shrink)

This paper considers Gianni Vattimo’s rejection of metaphysical conceptions of being in favor of a hermeneutic ontology developed along the lines of ‘weak thought.’ I argue that Vattimo’s critique neglects an abiding pluralism within the very history of metaphysical thought itself; at least some metaphysical conceptions of being in that history do not fall prey to his critique. To establish my claim I turn to Thomas Aquinas, whose metaphysics is couched within a larger theological context and presents itself dynamically, thereby (...) expressing some of the very features that Vattimo himself accords to Being. (shrink)

Averroes is well-known for his controversial thesis that there is only one separate intellect for all humankind. This article provides a detailed analysis of Averroes’s Unity Argument from his Long Commentary on De Anima, which argues from unified intelligible concepts to a single transcendent intellect. I set out the Unity Argument in its textual and philosophical context, explain exactly how the argument works on a new interpretation of its infinite regress, and offer some brief suggestions as to how it might (...) be further evaluated in light of alternative ancient and medieval theories. Ultimately, I demonstrate that the Unity Argument is Averroes’s most important philosophical argument for his distinctive view of intellect. (shrink)

The paper deals with a type of whole and part that can be found in Aquinas’ work and to which no attention has been paid so far. This type of whole and part can be called metaphysical whole and metaphysical part, respectively. In the paper, metaphysical whole and part are put forth on the problem of the logical and metaphysical structure of a common nature.

The so-called ‘intellectus essentiae argument’ has constituted one of the resources of some 13th century authors, to establish the ‘real distinction’ between essence and being in every creature. This argument is also present in Aquinas’ De Ente et Essentia, a work in which, the philosopher is believed to have tried to demonstrate the ‘real distinction or composition’ as well. Now, it is precisely the meaning and scope of this argument regarding the demonstration of the ‘real distinction’ in Thomas’ argumentation that (...) has been object of recent debate among specialists. In this sense, we intend in this article to first expose the argument in the context of the work to which it belongs, then concentrate on the opinions of the different commentators, and finally outline our conclusions based on the interpretations we consider the most accurate. (shrink)

This article seeks to advance a Thomistic metaphysics of creation in light of certain claims made by Stephen Hawking on the beginninglessness of the universe. I start with an exploration of Hawking's proposal that a beginningless universe entails an uncreated universe. This propels me into Aquinas's contention that a created beginningless universe is indeed possible, and thence I consider the metaphysics behind Thomas's position in this regard. Given this metaphysics of creation, I contend that there follow some interesting conclusions with (...) regard to our notion of a creator God and the means for establishing the existence of such. (shrink)

In this paper we present the standard Thomistic view concerning substances and their parts. We then note some objections to that view. Afterwards, we present Aquinas’s Christology, then draw an analogy between the relation that holds between the Second Person and the assumed human nature, on the one hand, and the relation that holds between a substance whole and its substance parts, on the other. We then show how the analogy, which St. Thomas himself drew at points, is useful for (...) providing a theory that answers the objections that the standard Thomistic view faces. Finally we answer objections to our approach. We conclude that there is a hylomorphic theory, founded on an analogy from Aquinas’s Christology, that fits well with the empirical data concerning substance parts, on which some complete created material substances have other complete created material substances as parts. (shrink)

Most contemporary philosophers of action agree on the following claims. Firstly, the possibility of deviant or wayward causal chains poses a serious problem for the standard-causal theory of action. Secondly, we can distinguish between different kinds of deviant causal chains in the theory of action. In particular, we can distinguish between cases of basic and cases of consequential deviance. Thirdly, the problem of consequential deviance admits of a fairly straightforward solution, whereas the possibility of basic deviance constitutes a separate and (...) difficult problem that requires its own solution. I will argue that the problem of basic deviance is no more troublesome than the problem of consequential deviance, as a solution to the former is implicit in the standard solution to the latter. (shrink)