Alexander James Bird

Emergent properties are intended to be genuine, natural higher level causally efficacious properties irreducible to physical ones. At the same time they are somehow dependent on or 'emergent from' complexes of physical properties, so that the doctrine of emergent properties is not supposed to be returned to dualism. The doctrine faces two challenges: (i) to explain precisely how it is that such properties emerge - what is emergence; (ii) to explain how they sidestep the exclusion problem - how it is that there is room for these properties to be causally efficacious, given the causal completeness of the physical. In this paper I explain how functional properties can meet both challenges.

In his (2002) Gonzalo Rodriguez-Pereyra provides a powerful articulation of the claim that Resemblance Nominalism provides the best answer to the so-called Problem of Universals. Resemblance Nominalism has not been popular for some time, and one influential reason for this is the widespread belief that Resemblance Nominalism cannot dispense with all universals. The realist critics appeal to what is known as Russell’s Regress (cf. Russell 1997). If properties are to be explained in terms of one object’s resembling another, then this seems to leave the relational property of resemblance itself unexplained. The critics’ objection is that this property itself must be explained by a dyadic universal of resemblance.

I show that Armstrong’s view of laws as second-order contingent relations of ‘necessitation’ among categorical properties faces a dilemma. The necessitation relation confers a relation of extensional inclusion (‘constant conjunction’) on its relata. It does so either necessarily or contingently. If necessarily, it is not a categorical relation (in the relevant sense). If contingently, then an explanation is required of how it confers extensional inclusion. That explanation will need to appeal to a third-order relation between necessitation and extensional inclusion. The same dilemma reappears at this level. Either Armstrong must concede that some properties are not categorical but have essential powers – or he is faced with a regress.

Let us call a property that is essentially dispositional a potency.1 David Armstrong thinks that potencies do not exist. All sparse properties are essentially categorical, where sparse properties are the explanatory properties of the type science seeks to discover. An alternative view, but not the only one, is that all sparse properties are potencies or supervene upon them. In this paper I shall consider the differences between these views, in particular the objections Armstrong raises against potencies.