Jonathan D. Jacobs

Possible worlds, concrete or abstract as you like, are irrelevant to the truthmakers for modality—or so I shall argue in this paper. First, I present the neo-Humean picture of modality, and explain why those who accept it deny a common sense view of modality. Second, I present what I take to be the most pressing objection to the neo-Humean account, one that, I argue, applies equally well to any theory that grounds modality in possible worlds. Third, I present an alternative, properties-based theory of modality and explore several specific ways to flesh the general proposal out, including my favored version, the powers theory. And, fourth, I offer a powers semantics for counterfactuals that each version of the properties-based theory of modality can accept, mutatis mutandis. Together with a definition of possibility and necessity in terms of counterfactuals, the powers semantics of counterfactuals generates a semantics for modality that appeals to causal powers and not possible worlds

We explain the thesis that human mental states are ontologically emergent aspects of a fundamentally biological organism. We then explore the consequences of this thesis for the identity of a human person over time. As these consequences are not obviously independent of one's general ontology of objects and their properties, we consider four such accounts: transcendent universals, kind-Aristotelianism, immanent universals, and tropes. We suggest there are reasons for emergentists to favor the latter two accounts. We then argue that within such ontologies, emergentism about properties pushes one to the stronger claim that there are emergent individuals, though not individuals which are dual to person's bodies—substance emergentism, but not substance dualism.

Causal powers, say, an electron’s power to repel other electrons, are had in virtue of having properties. Electrons repel other electrons because they are negatively charged. One’s views about causal powers are shaped by—and shape—one’s views concerning properties, causation, laws of nature and modality. It is no surprise, then, that views about the nature of causal powers are generally embedded into larger, more systematic, metaphysical pictures of the world. This dissertation is an exploration of three systematic metaphysics, Neo-Humeanism, Nomicism and Neo-Aristotelianism. I raise problems for the first two and defend the third. A defense of a systematic metaphysics, I take it, involves appealing to pre-theoretical commitments or intuitions, and theoretical issues such as simplicity or explanatory power. While I think that Neo-Aristotelianism is the most intuitive of the available general metaphysical pictures of the world, these kinds of intuitions do not settle the matter. The most widely held of the alternative pictures, Neo-Humeanism, is accepted in great part because of its theoretical power. In contrast, a systematic Neo-Aristotelian metaphysic is, at best, nascent. The way forward for the Neo-Aristotelian, therefore, is a contribution to an ongoing research program, generating Neo-Aristotelian views of modality, causation and laws of nature from the Neo-Aristotelian understanding of causal powers. The central argument of this dissertation is that such views are defensible, and so the Neo-Aristotelian metaphysic ought to be accepted.

Freedom and moral responsibility have one foot in the practical realm of human affairs and the other in the esoteric realm of fundamental metaphysics—or so we believe. This has been denied, especially in the metaphysics-bashing era occupying the first two-thirds or so of the twentieth century, traces of which linger in the present day. But the reasons for this denial seem to us quite implausible. Certainly, the argument for the general bankruptcy of metaphysics has been soundly discredited. Arguments from Strawson and others that our moral practices are too deeply embedded in human life to rest on anything as tenuous as a metaphysical doctrine far from the thoughts of ordinary people would seem to prove too much: we can easily imagine fantastic scenarios far from the thoughts of ordinary people—involving, say, alien manipulation or massive deception—that, if true, would clearly undermine claims to freedom and responsibility. For still other philosophers, the separation of the moral life from (some) metaphysical issues is prescriptive, not descriptive: it is a recommendation that we revise ordinary moral thought by severing its allegedly problematic links to metaphysics. (Some philosophers appear to hover undecided between such a prescriptive project and a Strawsonian descriptive claim.) We suspect that the prospects of retaining the binding force of ordinary moral thought, were such a reconceived moral practice widely embraced, are bleak. A transition to something closer to moral nihilism seems at least as likely. In any case, our interest here is in descriptive metaphysics, not revisionary. To say as we do that freedom and moral responsibility have a partly metaphysical character is not to suggest that they can be had only if some highly specific version of a particular metaphysical framework is correct. Instead, we suggest in what follows, it is a broadly neo-Humean metaphysics that is not hospitable to freedom (for reasons distinctive to the metaphysics), while a broadly neo-Aristotelian metaphysics is. But we also think (and it is the main aim of our paper to show) that different versions of the neo- Aristotelian metaphysics lead to rather different metaphysical accounts of free and responsible action. Specifically, we will argue that (1) the most satisfactory account of human freedom within the broadly neo-Aristotelian metaphysics is agent-causal, but that (2) two different versions of the general metaphysics will lead to important differences in the agent-causal account of freedom. Adjust the details of your general metaphysics, and the details of your account of freedom are transformed in significant ways. Action theory cannot properly be pursued in isolation from general metaphysics.