Abstract

Physicalist theories of science, theories of science that is which take physics to be the one basic science and which hold all other sciences to be reducible to physics, have thus far failed to provide a defensible account of cause, state, natural law and explanation. Physicalism has so far been confined to using traditional empiricist concepts of these features of theories. ;This dissertation formally constructs new concepts of scientific explanation by a theory, law of a theory and state description of a theory along lines acceptable to physicalists and indeed modeled on actual physical practice. It differs most noticably from standard empiricist accounts by taking a state description of an individual of a theory to be an exhaustive description of the individual in terms of the predicates of the theory and then demanding that the laws of the theory, taken together, allow us to generate new state descriptions for systems of individuals for regions of space and time in which the system evolves independently of external influences. The status of laws as laws is here no longer regarded in the traditional empiricist way as a function solely of their grammatical form and their truth. Instead lawlikeness is granted to laws in virtue of their membership in a system of laws, the system having the property of generating appropriate sets of new state descriptions. ;Further developments show that more than one system of laws can accomplish the same end result. Three systems of laws are studied in detail. They correspond to the systems of mechanistic laws, of conservation laws, and of force laws in classical physics. Algorithms are given for generating the latter two from the set of mechanistic laws. ;Finally, the physicalist doctrine of the final reducibility of all sciences to physics is embodied in a second type of system of laws which correlates state descriptions of a lower level with ones of a higher level . This second type thus comprises the principles of redescription by which the ontology of a higher level science is reduced to that of a lower