Space (and Its Perception): The First and Final Frontier

The primary test field for theories of perception has, over the centuries, been overwhelmingly the general problem of space perception and, in particular, distance perception. The first step in addressing this problem is a question of the most fundamental kind: What is space? It is not difficult to appreciate that resolution of the scientific problem of how space is perceived depends ultimately on the correctness of the scientific presumption of what space is apropos perception and action. The question can be refined: What kind of concept is “space”? The most dominant answer is that space is a mathematical concept. The defining properties are those identified in a formal geometric system, with the system of Euclid the most typical choice. A subordinate but nonetheless influential answer is that space is a physiological/psychological concept. Here, the emphasis is on the spatial properties that brain/mind might be presumed to prescribe to the world. The synthetic a priori properties of Kantian philosophy and the spatial patterns of organization of Gestalt psychology are primary examples. A third answer, hardly ever entertained, is that space is a biological/ecological concept. For this latter answer, the defining properties of space are to be found at the interface of animal and environment where their respective properties are complementary. Gibson’s (1950, 1979) claim that our practical and formal understanding of space should be founded on the layout of substantial surfaces that support actions rather than the points, lines, and planes of abstract geometry exemplifies the ecological stance. The many strands of thinking about space and geometry in the past few centuries, although often motivated by the first two answers, have provided a collection of proposals that inform the third answer and encourage its pursuit. Figure 1 summarizes the contributions of Descartes, Berkeley, and Kant pictured in terms of Descartes’s ECOLOGICAL PSYCHOLOGY, 16(1), 25–29 Copyright © 2004, Lawrence Erlbaum Associates, Inc.