Introduction

Everything whatever is determined by the physical. So goes the sweeping physicalist slogan. The thesis is “global” in the sense, among others, of being about all things and their properties everywhere everywhen. For each thing in the world and for any nonphysical property it may have – mental, semantic, valuational, whatever – physical conditions determine whether it has that property. An equivalent formulation of the thesis, current in the literature, is this: given the physical conditions that obtain in our world, and given any other world in which the same physical conditions obtain, the two worlds are the same as regards what things have what nonphysical properties. Worlds that are physical duplicates are duplicates in nonphysical conditions as well.

Which worlds? Probably the physically possible worlds (the ppws) – those in which the laws of physics hold. The sweeping thesis is not meant as a logically or conceptually necessary truth, and as we will see in Section 5, the empirical evidence for it warrants generalization only over the ppws. In any case, the thesis is “global” in a further sense: it generalizes over all the relevant worlds and over whole worlds to boot. This is especially clear in the following formulation, also current: in ppws, the physical conditions φ determine the nonphysical conditions ψ iff

where the same physical (or other) conditions obtain in both of two worlds just in case, for each such condition χ, χ obtains in one iff χ obtains in the other.