PSYCHOLOGY AND NEWTONIAN METHODOLOGY

According to Newton, the goals of natural philosophy comprise quantita tive generalizations and causal knowledge, the latter being paramount. Quantitative generalizations are sometimes explanatory, in psychology as elsewhere (the role of the Gaussian model in explaining the shape of the ROC curve in signal detection is discussed). However, in psycho logy, they are not explanatory when the human subject is considered qu a bearer of psychological states (beliefs, desires, and their ilk), bu t only when she is considered qua physical system. In the former case quantitative generalizations are, rather, to be causally explained. In this sense, psychology may be closer to the Newtonian methodological mark than contemporary physics.