ABSTRACT
The three brief definitions that serve as the header to this essay are intended to make a particular point concerning the relationship between the science of psychology and the science of biology. My thesis is that these two fields of science are related in the most intimate mannerpsychology is as much an integral part of biology as are anatomy, ecology, or physiology: Mental processes are as much biological processes as are endocrine secretions and spike action potentials. The student of mental processes who loses sight of this basic fact does so at the peril of losing sight of the most fundamental premise of psychobiology-psychoneural equivalence-the idea that mind is a brain function-and exposes himself to cultism, mysticism, and inconsistency outside the body of modern scientific thinking. To assert this premise so strongly is not to say that the emphases of psychology are not different from the emphases of anatomy for example. but rather to note that scientific psychology's origins and
goals are no more different from any of the other biological sciences than they are from each other. Psychologists typically find themselves in a separate department or institute from other biological scientists, but mainly because their methods and the specific objects of their research attention differ from those of other biological sciences, not because there is any fundamental distinction to be made between the intellectual or conceptual bases of the biological and psychological fields of inquiry. To propose a contrary view is implicitly to accept a kind of dualistic thinking that has decreasing acceptability in today's scientific thought.
