Two general approaches to the examination and understanding of psychological phenomena have been in place since the inception of scientific psychology—physiological and phenomenological. In a sense, the distinction has its modern roots in Descartes’ separation of mind from body as two distinct realities. As you might expect, physiological psychology is concerned with the body as it is involved in what we refer to as psychological. In particular, the focus has been on sensory and neurological processes. Phenomenology, in contrast, places its emphasis on human experience and consciousness, on one’s subjective condition as revealed through self-examination or introspection. These two traditions were both represented in the “new” experimental psychology but presented a difficulty in that they appeared to be irreconcilably opposed.

What is involved in each of these traditions will be the focus of this chapter. You should have a familiarity with what is proposed, why they are opposed, and whether their divergence can ever be resolved. In particular, we will consider:

• The development of research into physiology in terms of the nervous system and sensory processes.
• The phenomenological tradition and its incorporation into scientific psychology.
• The divergence between these two approaches and possible resolution of their disparity.