This volume has three goals with respect to the interplay between philosophy and behavioral psychology''s experimental, applied, and interpretive levels of knowing. It aims to examine core principles in the philosophy of science, as they are interpreted by and relate to behavioral psychology; how these core principles interact with different problem areas in the study of human behavior; and how experimental, applied, and interpretive analyses complement one another to advance the understanding of behavior and, in so doing, also the philosophy of science.