9311982 Humphreys The "received view" of how scientific theories in different domains are related to each other has been, for a number of years, a hierarchical model. At the base is physics, or elementary particle physics to be more precise. Particle physics is taken as the most fundamental of all sciences. Then come, in order, chemistry molecular biology, general biology, psychology, and the social sciences. Much work in the philosophy of science has been devoted to the relationship between adjacent levels within this science. Dr. Humphreys, in this project, is attempting to answer concerns about the inter-level relationship of properties. An example of major concern for philosophy and psychology has been the relation between psychological or computational properties and their underlying neurobiological/physical properties. Issues concerning the mind/body problem and the status of cognitive science depend directly on how this general question is answered. Dr. Humphreys is specifically addressing a new way to characterize the distinction between "emergent" and "nonemergent" properties. How, for example, can the mind "emerge" from the properties of the neurons that make up the brain? How does thought and memory come out of the chemical and electrical interactions that occur in this physical organ? The crucial point in looking at these relations is that the causal properties that the psychologist deals with (thoughts, emotions, memories) do not exist at the neurobiology level and only "emerge" at the level of psychology. The main focus of this research is the proper way to construe these emergent properties, with the distinction between internal and external relations as the guide to a correct treatment. Dr. Humphreys is using these investigations to extend existing accounts of scientific explanation to include emergent properties. ***