**2015/16 reading group**

In Michaelmas Term 2016 and Hilary Term 2016, the Metaphysics of Entanglement reading group focused on Barbara Vetter’s Potentiality (OUP, 2015) in 2015/16. Vetter offers a new theory of the metaphysics of modality, dispositions, and powers. Her central claim is that analytic metaphysics has made a mistake in thinking of modality in terms of possible worlds, which are global and maximal objects. A more fruitful way is to think of modality as residing intrinsically in particular objects, in the form of potentialities for certain effects—the real source of modality is local, rather than global.

**Sessions:**

Chapter 1: **The Project** (presented by George Darby)

Chapter 1 outlines the main reasons for thinking of modality in local, rather than global terms, explains the three desiderata that a metaphysical theory of modality must fulfill, and introduces the concept of potentiality.

Chapter 2: **Dispositions: Against the Standard Conception** (presented by Christopher Austin) handout

Chapter 2 argues that the standard linking of dispositions to conditionals runs into trouble if we want to be realists about dispositions, and suggests that dispositions are to be understood not in terms of a stimulus and a manifestation but in terms of the manifestation alone.

Chapter 3: **Dispositions: an Alternative Conception** (presented by Naoya Iwata) handout

Chapter 3 (i) draws on the semantics of ordinary terms and the desiderata on the metaphysics of modality to bolster the thesis that dispositions are individuated in terms of manifestations, and (ii) it elaborates the concept of potentiality.

Chapter 4: **Varieties of Potentiality** (presented by Martin Pickup) handout

Chapter 4 introduces important classifications of potentialities: the joint potentialities that objects possess together; the extrinsic potentialities that objects possess in virtue of possessing joint potentialities together with other objects; and iterated potentialities. In each case, we start with intuitive cases and merely generalize from there.

Chapter 5: **Formalizing Potentiality** (presented by Maximilian Zachrau) handout

A formal language for potentiality is introduced, which allows us to express such potentiality ascriptions as ‘I have a potentiality to be such that I am sitting or you are standing’, etc. Potentiality is governed by axioms and rules that are in parallel with those formetaphysicalmodality: in particular, closure under logical implication, distribution over disjunction, and implication by actuality.

Chapter 6: **Possibility: Metaphysics and Semantics **(presented by Daniel Kodaj) handout

Chapter 6 explores how the account deals with some standard cases of metaphysical possibility and necessity, and how it meets the two constraints of formal adequacy and semantic utility.

Chapter 7: **Objections** (presented by David Glick) handout

The final chapter goes through counterexamples of two kinds: potentialities without the corresponding possibilities, and possibilities without the corresponding potentialities. The chapter also sketches a (Stalnakerian) account of possible worlds as unmanifested potentialities of the world, and discusses the relation between potentiality and time.