Abstract

The progress of psychology as scientific theory has been handicapped by the circumstance that it has been inclined to deal with two kinds of problems: on the one hand, with emotions, instincts, complexes, ideas, etc.; on the other, with the working of the sense-organs and of the central and sympathetic nervous system. To approach the first task it has had to create a system of mentalistic or introspective concepts, like the ones mentioned; to deal with the second enterprise it has adopted the physical language used by the natural sciences.