ABSTRACT
When psychology, after the turn of the century, renamed itself the “study of behavior” and turned away from the profound thoughts of William James, Mark Baldwin, and other luminaries, it became unfashionable to go foraging in the fields of philosophy. This isolationism had profound consequences. It froze the psychological establishment in the conviction that their science had to fit the model of Newtonian physics and a simplified positivism was all that would be needed as epistemology. One manifestation of this development was the widely successful suppression of the difference between empiricism and realism. In the study of animal behavior, this led “hard-nosed empiricists” to the belief that the world as they conceived it (and therefore perceived it) was the only world there could be for human observers and animals alike. As a result, there seemed to be no need for the consideration that neither the perceptual environment (Merkwelt) nor the sphere of action (Wirkwelt) could possibly be the same for organisms endowed with different equipment for sensing and acting (von Uexküll, 1934). Epistemology was not something animal psychologists felt obliged to deal with.
