• Unity of Science
    Cambridge University Press. 2021.
    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 phenomen…Read more
  • Bundle Theory with Kinds
    Philosophical Quarterly 69 (277): 838-857. 2019.
    Is it possible to get by with just one ontological category? We evaluate L.A. Paul's attempt to do so: the mereological bundle theory. The upshot is that Paul's attempt to construct a one category ontology may be challenged with some of her own arguments. In the positive part of the paper we outline a two category ontology with property universals and kind universals. We will also examine Paul's arguments against a version of universal bundle theory that takes spatiotemporal co-location instead …Read more
  • The Law of Non-Contradiction as a Metaphysical Principle
    Tuomas Tahko
    Australasian Journal of Logic 7 32-47. 2009.
    The goals of this paper are two-fold: I wish to clarify the Aristotelian conception of the law of non-contradiction as a metaphysical rather than a semantic or logical principle, and to defend the truth of the principle in this sense. First I will explain what it in fact means that the law of non-contradiction is a metaphysical principle. The core idea is that the law of non-contradiction is a general principle derived from how things are in the world. For example, there are certain constraints …Read more
  • Structure
    Tuomas Tahko
    In Michael J. Raven (ed.), The Routledge Handbook of Metaphysical Grounding, Routledge. pp. 387-395. 2020.
    An exploration of ground’s connections to structure (joint-carving, naturalness). The notion of structure is often invoked in connection to ground, because grounding is understood to impose constraints on the ‘structure of reality’. There is another, technical sense of structure, sometimes captured with reference to the notion of ‘joint-carving’. Both of these senses of structure as well as their potential connections are discussed.
  • A Priori or A Posteriori?
    Tuomas Tahko
    In Ricki Bliss & James Miller (eds.), , Routledge. pp. 353-363. 2020.
    This article discusses the role of a priori and a posteriori knowledge and methods in metaphysics and metametaphysics. Issues discussed include the viability of the distinction, the continuity of a priori and a posteriori methods, connections to modal epistemology, and the role of the distinction for science and naturalistic metaphysics.
  • Ontological Dependence
    Stanford Encyclopedia of Philosophy. 2020.
    Ontological dependence is a relation—or, more accurately, a family of relations—between entities or beings. For there are various ways in which one being may be said to depend upon one or more other beings, in a sense of “depend” that is distinctly metaphysical in character and that may be contrasted, thus, with various causal senses of this word. More specifically, a being may be said to depend, in such a sense, upon one or more other beings for its existence or for its identity. Some varieties…Read more
  • A Survey of Logical Realism
    Synthese 198 (5): 4775-4790. 2021.
    Logical realism is a view about the metaphysical status of logic. Common to most if not all the views captured by the label ‘logical realism’ is that logical facts are mind- and language-independent. But that does not tell us anything about the nature of logical facts or about our epistemic access to them. The goal of this paper is to outline and systematize the different ways that logical realism could be entertained and to examine some of the challenges that these views face. It will be sugges…Read more
  • An Introduction to Metametaphysics
    Cambridge University Press. 2015.
    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 metaon…Read more