The present PhD dissertation aims to examine the relation between modality and change in Aristotle’s metaphysics. -/- On the one hand, Aristotle supports his modal realism (i.e., worldly objects have modal properties - potentialities and essences - that ground the ascriptions of possibility and necessity) by arguing that the rejection of modal realism makes change inexplicable, or, worse, banishes it from the realm of reality. On the other hand, the Stagirite analyses processes by means of modal notions (‘change is the (...) actuality of what is virtual insofar as it is virtual’). In other words: to grasp what change is, one has to resort to the modal idiom of potentialities, while the fact that there is change is indicative of the fact that nature is full of modal properties. -/- Aristotle’s modal and kinetic realism finds a negative in the figure of the Megaric Diodorus Kronus. The polemical situation of Greek philosophy has indeed the dialectical advantage of not opposing the Aristotelian position to a sui generis straw man. Both in its reduction of modal judgements to temporal quantifications and in its dissolution of the reality of the state-of-being-in-motion in favour of a cinematographic view of processes, the philosophical figure of reductionist antirealism embodied by Diodorus constitutes an alternative that takes the opposite view of Aristotle’s realism. -/- The present study is structured as a discussion between these two positions. In the face of Diodorus’ antirealist challenges, Aristotle articulates modal and kinetic considerations: the answers he gives to Diodorus’ puzzles thus provide valuable insight into his metaphysics. Moreover, the examination of Aristotle’s and Diodorus’ metaphysics, because of their insight and originality, will not fail to interest the philosopher concerned with the metaphysical foundations of modern physics, insofar as the entanglement between modalities and processes is nowadays at the core of mechanics (phase spaces, path integrals, etc.). (shrink)

This paper is inspired by and develops on E. J. Lowe’s work, who writes in his book The Possibility of Metaphysics that ‘metaphysical possibility is an inescapable determinant of actuality’ (1998: 9). Metaphysics deals with possibilities – metaphysical possibilities – but is not able to determine what is actual without the help of empirical research. Accordingly, a delimitation of the space of possibilities is required. The resulting – controversial – picture is that we generally need to know whether something is (...) possible before we can know whether it is actual. In order to appreciate this picture, we need to understand Lowe’s slogan: ‘essence precedes existence’ (Lowe 2008: 40). This slogan has both an ontological and an epistemic reading. The ontological reading is related to the now familiar idea that essence grounds modality, as popularised by Kit Fine. The epistemic reading suggests that we can know the essence of some entity before we know whether or not that entity exists. However, this idea is often met with puzzlement and Lowe himself sadly passed away before he had a chance to clarify this framework. I will present the framework as I understand it, develop it on my own terms, and put forward a qualified defence of it. I will also illustrate how the framework can be put to use with a case study concerning the discovery of transuranic elements. (shrink)

Unity of science was once a very popular idea among both philosophers and scientists. But it has fallen out of fashion, largely because of its association with reductionism and the challenge from multiple realisation. Pluralism and the disunity of science are the new norm, and higher-level natural kinds and special science laws are considered to have an important role in scientific practice. What kind of reductionism does multiple realisability challenge? What does it take to reduce one phenomenon to another? How (...) do we determine which kinds are natural? What is the ontological basis of unity? In this Element, Tuomas Tahko examines these questions from a contemporary perspective, after a historical overview. The upshot is that there is still value in the idea of a unity of science. We can combine a modest sense of unity with pluralism and give an ontological analysis of unity in terms of natural kind monism. This title is available as Open Access on Cambridge Core. (shrink)

Discussion of grounding-theoretic accounts of truthmaking in terms of the theoretical role of “catching cheaters”.

The present paper discusses different approaches to metaphysics and defends a specific, non-deflationary approach that nevertheless qualifies as scientifically-grounded and, consequently, as acceptable from the naturalistic viewpoint. By critically assessing some recent work on science and metaphysics, we argue that such a sophisticated form of naturalism, which preserves the autonomy of metaphysics as an a priori enterprise yet pays due attention to the indications coming from our best science, is not only workable but recommended.

In discussions about whether the Principle of the Identity of Indiscernibles is compatible with structuralist ontologies of mathematics, it is usually assumed that individual objects are subject to criteria of identity which somehow account for the identity of the individuals. Much of this debate concerns structures that admit of non-trivial automorphisms. We consider cases from graph theory that violate even weak formulations of PII. We argue that (i) the identity or difference of places in a structure is not to be (...) accounted for by anything other than the structure itself and that (ii) mathematical practice provides evidence for this view. We want to thank Leon Horsten, Jeff Ketland, Øystein Linnebo, John Mayberry, Richard Pettigrew, and Philip Welch for valuable comments on drafts of this paper. We are especially grateful to Fraser MacBride for correcting our interpretation of two of his papers and for other helpful comments. CiteULike Connotea Del.icio.us What's this? (shrink)

What is the new essentialist asking us to accept? Not that there are natural kinds, nor that there are intrinsic causal powers. These things could be accepted without a commitment to essentialism. They are asking us to accept something akin to the Kripke‐Putnam position: a metaphysical theory about kind‐membership in virtue of essential properties. But Salmon has shown that there is no valid argument for the Kripke‐Putnam position: no valid inference that gets us from reference to essence. Why then should (...) we accept essentialism? A remaining reason is Ellis's argument by display: we should buy essentialism because of the benefits it will bring. But are these benefits real? The problem is that the putative benefits of essentialism – that the laws of nature are necessary, that the problem of induction is solved, and so on – look actually to be the assumptions of Ellis's theory. If that is the case, there is no real benefit to be gained from adopting the theory. The argument for essentialism is therefore underdetermined and it remains possible to accept natural kinds into one's ontology without accepting their corresponding essences. (shrink)

In this paper, I discuss how to distinguish between ontological categories and ordinary categories. Using an argument against van Inwagen’s proposed account of what makes a category ontological as a springboard, I argue that if ontological categories are modally robust, then ontological categories need to be understood hyperintensionally. This conclusion opens up a wide range of new ways to define ‘ontological category’, and I close by briefly outlining one such way in order to illustrate the advantages of embracing hyperintensionality in (...) this debate. (Published Open Access). (shrink)

Several non-naturalist philosophers look for ways to maintain the objectivity of morals without making any ontological commitments. Recently Derek Parfit proposed an account of non-ontologically existing irreducible moral properties. My first aim in this paper is to outline that such an account is doomed to fail. My second aim in this paper is to argue that irreducible moral properties can be integrated with adaptions into an ontological framework such as E.J. Lowe’s four-category ontology. If it can be shown that irreducible (...) moral properties have a proper place in such an ontology, then there is no need to distinguish between an ontological and non-ontological mode of existence, which, in turn helps to eschew the obscurities that this distinction brings in its wake. (shrink)