Yet the behavioristic or physicalistic or "guillotine" approach to man is profoundly antibiological. In the study of a
living species, the biologist is vitally interested in learning the nature of that species' distinctive means of
survival—since he recognizes that such information constitutes an indispensable key to the species' behavior. In the
case of man, it is clear that his distinctive way of dealing with reality, of maintaining his existence, is through the
exercise of his conceptual faculty. All of his unique attainments—scientific knowledge, technological and industrial
achievements, art, culture, social institutions, etc.—proceed from and are made possible by his ability to think. It is
upon his ability to think that his life depends. A biocentric approach, therefore, requires that one grant prime
importance to man's conceptual faculty in the study of his behavior.
The ultimate source of all man's knowledge is the evidence of reality provided by his senses. Through the
stimulation of his various sensory receptors, man receives information which travels to his brain in the form of
sensations (primary sensory inputs). These sensory inputs, as such, do not constitute knowledge; they are only the
material of knowledge. Man's brain automatically retains and integrates these sensations—thereby forming
percepts. Percepts constitute the starting point and base of man's knowledge: the direct awareness of entities, their
actions and their attributes.
In our discussion of the nature of living organisms (Chapter Two), we saw that an organism sustains itself
physically by taking materials from the environment, reorganizing them and achieving a new integration which
converts these materials into the organism's means of survival. We can observe an analogous phenomenon in the
process by which a consciousness apprehends reality. Just as integration is the cardinal principle of life, so it is the
cardinal principle of knowledge. This principle is operative when, in the brains of men or animals, disparate
sensations are automatically retained and integrated (by nature's "programming," in effect) in such a way as to
produce a perceptual awareness of entities—an awareness which men and animals require for their survival. (The
principle of integration is central, as we shall see, to the process of concept-formation also—except that here the
integration is not automatic or "programmed" by nature; conceptual integration must be achieved volitionally by
man.)