PERCEPTION 89 



Very early in the individual's experience he must have 

 noticed that elements such as colors, shapes, tastes, odors, 

 tensions, feelings, decisions, tendencies, and the like unite 

 into clusters having a certain permanency of existence and 

 of recurrence. Knowledge reveals not merely the fact of 

 such elements as these, but also the fact of their togetherness 

 in certain associative wholes. The unitary character of 

 such wholes is determined not merely by the fact of persist- 

 ence and recurrence but also by the fact that changes 

 tend to occur in clusters, i.e., changes in certain of the 

 elements tend always to be associated with changes in other 

 elements. By the observation of these persisting and recur- 

 ring associations, undergoing collective changes, the indi- 

 vidual selects certain wholes to which he attaches an indi- 

 viduality. These complexes he calls "objects," though it 

 must be recognized that such a term tends to suggest an 

 opposition to "subjects' and "subjective" — an implica- 

 tion which is misleading at this point. Certain complexes 

 exhibiting shape, color, size, spatial and temporal location, 

 hardness, rest or motion, and the like are called "physical 

 objects," changes in such objects being illustrated by break- 

 ing, dissolving, and burning. Certain complexes of this 

 kind are also called "physical media," since they have the 

 peculiar power of affecting other physical objects in certain 

 describable ways; for example, a glass of water is such a 

 medium since it causes a straight stick to appear bent when 

 immersed in it; also a microscope is such a medium since it 

 causes a small object to appear large when placed under it. 

 Certain other clusters are called "biological objects," one of 

 which is the individual's own organism; this also has the 

 power to induce changes in physical objects, as in the case 

 of an object which appears double when the individual is 

 under the influence of drugs or subjecting his eyeball to 

 pressure. Another cluster the individual calls "mind" or 

 "consciousness"; this again has the power to induce changes 

 in physical objects; for example, an object may be changed 

 by suggestion or by alteration in emotional attitude. Finally 



