Tuomas E. Tahko

In formal ontology, infinite regresses are generally considered a bad sign. One debate where such regresses come into play is the debate about fundamentality. Arguments in favour of some type of fundamentalism are many, but they generally share the idea that infinite chains of ontological dependence must be ruled out. Some motivations for this view are assessed in this article, with the conclusion that such infinite chains may not always be vicious. Indeed, there may even be room for a type of fundamentalism combined with infinite descent as long as this descent is “boring,” that is, the same structure repeats ad infinitum. A start is made in the article towards a systematic account of this type of infinite descent. The philosophical prospects and scientific tenability of the account are briefly evaluated using an example from physics

When I say that my conception of metaphysics is Aristotelian, or neo-Aristotelian, this may have more to do with Aristotle’s philosophical methodology than his metaphysics, but, as I see it, the core of this Aristotelian conception of metaphysics is the idea that metaphysics is the first philosophy . In what follows I will attempt to clarify what this conception of metaphysics amounts to in the context of some recent discussion on the methodology of metaphysics (e.g. Chalmers et al . (2009), Ladyman and Ross (2007)). There is a lot of hostility towards the Aristotelian conception of metaphysics in this literature: for instance, the majority of the contributors to the Metametaphysics volume assume a rather more deflationary, Quinean approach towards metaphysics. In the process of replying to the criticisms towards Aristotelian metaphysics put forward in recent literature I will also identify some methodological points which deserve more attention and ought to be addressed in future research

Recent work on Natural Kind Essentialism has taken a deflationary turn. The assumptions about the grounds of essentialist truths concerning natural kinds familiar from the Kripke-Putnam framework are now considered questionable. The source of the problem, however, has not been sufficiently explicated. The paper focuses on the Twin Earth scenario, and it will be demonstrated that the essentialist principle at its core (which I call IDENT)—that necessarily, a sample of a chemical substance, A, is of the same kind as another sample, B, if and only if A and B have the same microstructure—must be re-evaluated. The Twin Earth scenario also assumes the falsity of another essentialist principle (which I call INST): necessarily, there is a 1:1 correlation between (all of ) the chemical properties of a chemical substance and the microstructure of that substance. This assumption will be questioned, and it will be argued that, in fact, the best strategy for defending IDENT is to establish INST. The prospects for Natural Kind Essentialism and microstructural essentialism regarding chemical substances will be assessed with reference to recent work in the philosophy of chemistry. Finally, a weakened form of INST will be presented.

How do we come to know metaphysical truths? How does metaphysical inquiry work? Are metaphysical debates substantial? These are the questions which characterize metametaphysics. This book, the first systematic student introduction dedicated to metametaphysics, discusses the nature of metaphysics - its methodology, epistemology, ontology and our access to metaphysical knowledge. It provides students with a firm grounding in the basics of metametaphysics, covering a broad range of topics in metaontology such as existence, quantification, ontological commitment and ontological realism. Contemporary views are discussed along with those of Quine, Carnap and Meinong. Going beyond the metaontological debate, thorough treatment is given to novel topics in metametaphysics, including grounding, ontological dependence, fundamentality, modal epistemology, intuitions, thought experiments and the relationship between metaphysics and science. The book will be an essential resource for those studying advanced metaphysics, philosophical methodology, metametaphysics, epistemology and the philosophy of science.

In this paper I will offer a novel understanding of a priori knowledge. My claim is that the sharp distinction that is usually made between a priori and a posteriori knowledge is groundless. It will be argued that a plausible understanding of a priori and a posteriori knowledge has to acknowledge that they are in a constant bootstrapping relationship. It is also crucial that we distinguish between a priori propositions that hold in the actual world and merely possible, non-actual a priori propositions, as we will see when considering cases like Euclidean geometry. Furthermore, contrary to what Kripke seems to suggest, a priori knowledge is intimately connected with metaphysical modality, indeed, grounded in it. The task of a priori reasoning, according to this account, is to delimit the space of metaphysically possible worlds in order for us to be able to determine what is actual.