Establishing Dispositionalism as a viable theory of modality requires the successful fulfilment of two tasks: (i) showing that all modal truths can be derived from truths about actual powers, and (ii) offering a suitable metaphysics of powers. These two tasks are intertwined: difficulties in one can affect the chances of success in the other. In this paper, I generalise an objection to Dispositionalism by Jessica Leech and argue that the theory in its present form is ill-suited to account for de re truths about merely possible entities. I argue that such difficulty is rooted in a problem in the metaphysics of powers. In particular, I contend that the well-known tension between two key principle of powers ontology, namely Directedness (all powers are “for” their manifestation) and Independence (some powers might fail to bring about their manifestation) has received an unsatisfactory solution so far, and that it is this unsatisfactory solution concerning the status of “unmanifested manifestations” that makes it hard for Dispositionalism to account for mere possibilia. I develop a novel account of the status of unmanifested manifestations and an overall metaphysics of powers which allows to better respond to Leech's objection and handle mere possibilia. The central idea of the proposal is that unmanifested manifestations are akin to mere logical existents, and are best characterised as non-essentially non-located entities.

In this paper I argue that even the most radical metaphysics of powers (such as that adopted by Mumford & Anjum, Cartwright, or Groff) are compatible with eternalism. I first offer a taxonomy of powers ontologies, and attempt to characterise the difference between moderate and radical powers ontologies-the latter are characterised by an emphasis on production and dynamicity. I consider an argument by C. Friebe to the effect that the productive character of powers is inconsistent with Eternalism and find it wanting. I then elucidate the notion of dynamicity that radical powers theorists employ by making apparent their link with an ontology of irreducible processes. Finally, I respond to an argument by Donatella Donati to the effect that eternalism entails a reductive account of change which is inconsistent with process ontologies, and show that the the two are compatible. I conclude that we have no reason to think that radical powers metaphysics (and, a fortiori, every powers ontology) are not compatible with eternalism. A broadly Neo-Humean conception of the world, paradigmatically embodied by Lewis' claim that 'all there is to the world is a vast mosaic of local matters of particular fact, just one little thing and then another' (Lewis 1986: ix) has been, at least implicitly, the background world-view of most metaphysical theorising in the last decades of the twentieth century. Recently, however, this paradigm is being put 'under serious pressure within analytic metaphysics' (Groff & Greco, 2013: 1) by a rival, broadly Neo-Aristotelian picture of reality, spearheaded by the idea that there are real causal powers that establish necessary connections between existents. i

Forthcoming in Sandstad & Jansen (eds.) Neo-Aristotelian Perspectives on Formal Causation, Routledge §1. Causation, Powers and Explanation Here's a story about causation that will surely sound familiar:The Aristotelian teaching of causes lasted in the official Western culture until the Renaissance. When modern science was born, formal and final causes were left aside as standing beyond the reach of experiment; and material causes were taken for granted in connection with all natural happenings--though with a definitely non-Aristotelian meaning, since in the modern world view matter is essentially the subject of change, not 'that out of which a thing comes to be and persists'. Hence of the four Aristotelian causes only the efficient cause was regarded as worthy of scientific research. (Bunge 1959: 32).This account is surely oversimplified, and most likely any historian of science will protest that it does not reflect the actual practice of modern science. However, it is a much more accurate depiction of what philosophers, both modern and contemporary, believed happened with the advent of modernitynormally equating efficient causation with mechanical causation, and causal explanation with mechanical explanations. That the equation of causation with efficient causation was widespread to the point of being commonsensical is nicely illustrated by Hume, who attacking efficient causes (billiard balls hitting each other, and so on) is confident to have dismantled causation tout court.Unfortunately, it turns out that we do need other kinds of explanations in our scientific practice; in particular, traces of the much maligned final explanation appears in many of the special sciences, and the very way we speak of laws of nature betrays this fact. The only problem is that the metaphysics elaborated in the meanwhile -in particular, our current received neo-Humean metaphysics, really struggles to make sense of final explanations and final causes. Final causes are just hard to square with the view that the world is nothing but a mosaic of discrete, unrelated particular matters of fact.On the other hand, a metaphysics admitting irreducibly dispositional properties (powers) seems well suited to ground teleological explanations because it can provide a metaphysical correlate to the telos in the explanation. Friends of powers often speak of powers being directed towards something -their manifestations, what the power are for. It is relatively easy, then, to provide a realist theory of final explanations within such metaphysics, because there are obvious candidates to play the role of final causes -the 'what for the sake of which' just is the manifestation of the relevant power(s). Efficient 1 causal explanations, on the other hand, would be grounded in the powers themselves: they are the 'whence the source of change'.Insofar as i) final explanations are required by our best scientific theories, ii) power metaphysics does a better job in grounding them, and iii) we want to be realist about explanation, we have a good naturalistic ar...

There is a tension between Dispositionalism––the view that all metaphysical modality is grounded in actual irreducible dispositional properties––and the possibility of time travel. This is due to the fact that Dispositionalism makes it much harder to solve a potentiality-based version of the grandfather paradox. We first present a potentiality-based version of the grandfather paradox, stating that the following theses are inconsistent: 1) time travel is possible, 2) powers fully ground modality, 3) self-defeating actions are impossible, 4) time-travellers retain their intrinsic powers upon time-travelling, and 5) time-travellers are ordinary agents with basic intrinsic potentialities. We then consider a number of potential solutions, and find them wanting. We argue that the metaphysical impossibility of performing a self-defeating action acts as a necessary perfect mask––while time-travel lets us “slip” the potentiality under the mask, thus generating the contradiction. We conclude considering what are the options for the dispositionalist.

Dispositionalism is the theory of modality that grounds all modal truths in powers: all metaphysically possible and necessary truths are to be explained by pointing to some actual power, or absence thereof. One of the main reasons to endorse dispositionalism is that it promises to deliver an especially desirable epistemology of modality. However, so far this issue has not be fully investigated with the care it is due. The aim of this paper is to fill this gap. We will cast some doubts on whether the dispositionalist really is in a better position to explain our modal knowledge. In fact, we argue that there is a tension between some core tenets of a powers metaphysics and the very features that make dispositionalism the ideal backdrop for a desirable epistemology of modality. We conclude that this leaves dispositionalists who want to deliver the promised epistemology with a hard, currently unfulfilled, task.