Individuals in Metaphysics and the Philosophy of Biology

Philosophers of biology and metaphysicians are both interested in the nature of biological individuals or organisms. Despite this, there has so far been very little contact between the two. This thesis argues that this should change. It argues that metaphysics can contribute to key debates about the nature of biological individuals in the philosophy of biology, but also that the philosophy of biology is relevant to more general metaphysical debates about material objects. Chapters 1-3 are concerned with two of the main debates about the nature of biological individuals in the philosophy of biology: the Problem of Biological Individuality, and the Substance-or-Process Question. I argue that some of the main positions in these debates face metaphysical worries. The upshot is that a particular view about the nature of biological individuals should be preferred: biological individuals are substances and units of selection. Chapter 4 argues that serious metaphysical views are in tension with the existence of biological individuals. Importantly, it demonstrates that the outcome of debates in the philosophy of biology discussed in earlier chapters is dependent on the answers to metaphysical questions about material objects. Chapter 5 argues that the philosophy of biology is relevant to the Special Composition Question in metaphysics, which asks, ‘under what conditions do smaller things make up something bigger?’. It argues that solutions to the Problem of Biological Individuality allow metaphysicians to generate a precise and biologically informed answer to the Special Composition Question. Finally, chapter 6 motivates a novel way of understanding the Problem of Biological Individuality which would allow philosophers of biology to entirely sidestep the metaphysical worries facing their views discussed in chapters 1 to 4. The thesis should be of interest to philosophers of biology interested in biological individuality, and metaphysicians interested in the nature of substances, composition, and personal identity.