Space Perception and the Psychologist's Fallacy in James's Principles

Abstract

The theory of space perception presented in The Principles of Psychology is one of the most coherent and developed arguments of that important book. Space perception was of great significance for James as a test case for his doctrine of psychophysiological unity (to be much more provocatively developed in his account of the stream of consciousness and of the emotions). James considered himself to be a sensationalist, by which he meant that all of perception and even all of thought had to have its origin in the mind’s reaction to the body’s physiological condition. He opposed those whom he called “psychological stimulists”—many of whom, such as Wundt or Helmholtz, we might, confusingly, dub sensationalists—those who believed that sensations were punctate and meaningless mental atoms. If sensations were mere punctate mental states in this way, then all meaningful psychological states would have to involve something in addition to sensation, and it was this idea that James opposed. If one were to erect a real psychology of thought or emotion on a sensationalist basis, then sensations had better be much richer and more interesting than James’s opponents were willing to allow. Space perception thus became a battleground: Is our knowledge of space based on attending to spatial properties already found in sensations, as James would argue, or is it the result of adding spatial structure to originally nonspatial sensory awareness, as the psychical stimulists thought? As I shall show, James believed his opponents were factually incorrect about the spatial character (or lack of it) of sensations. He also thought they had fallen prey to the most pernicious methodological problem in psychology: the psychologist’s fallacy. I shall trace both the empirical and methodological aspects of James’s argument, and then suggest ways in which James’s ideas still have relevance for modern psychologists.