How Superduper Does a Physicalist Supervenience Need to Be?

It has recently been made clear that the standard formulations of the supervenience relation – weak, global and strong, among others – are too programmatic to be the full answer to a physicalist’s prayers. All the standard formulations present the supervenience of one set of properties on another in terms of property correlations, without placing any constraints on the dependency relation eVecting these correlations. It turns out that such abstract characterizations do not ensure that properties supervening upon (what are assumed to be) physicalistically acceptable base properties are themselves physicalistically acceptable. Most disastrously, the standard formulations of supervenience turn out one and all to permit supervenient properties to be emergent in a way at odds with materialism. What physicalism needs to support a materialist metaphysics is ‘superdupervenience’ – supervenience that guarantees that supervenient properties are ‘nothing over and above’ their physicalistically acceptable base properties. Terence Horgan (p. 563) has suggested that the following constraint will do the job: