Formal plane geometry has been contrasted with an unformalized and quite unfamiliar
geometry of surfaces. But the latter is more appropriate for describing the environment
in which we perceive and behave, because a surface can be seen whereas a plane
cannot. The differences between a plane and a surface have been pointed out.

A tentative list of the main features of surface layout has been proposed. The
definitions are subject to revision, but terms of this sort are needed in ecology,
architecture, design, the biology of behavior, and the social sciences instead of the
planes, forms, lines, and points of geometry. The term object, especially, has been
defined so as to give it a strictly limited application unlike the general meaning it has
in philosophy and psychology.

The fundamental ways in which surfaces are laid out have an intrinsic meaning for
behavior unlike the abstract, formal, intellectual concepts of mathematical space.

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