If the preponderant number of human purposes are developed in relation to fundamental retroflexes in the manner above suggested, it is natural that these purposes should be interpretable as psychical representations of biological instruments in the struggle for existence. All of the retroflexes have an obvious application to the requirements of survival. They represent mechanisms indispensable to the existence of those animal species which manifest flexibility of response. Consequently, there is a close logical relationship between purpose and biological adaptation, which explains the readiness with which such adaptation is interpreted in purposive terms. The fact that nature is so organized as to make life possible and to permit the fulfillment of our purposes seems to be a remarkable coincidence. However, the scientifically enlightening explanation has the converse form, and interprets purposes in terms of their survival values or biological utility. Since our purposes are the creation of evolution, it is not wonderful that the determinants of evolution should be suited to produce and satisfy them.
Now, it must be confessed that a great many human purposes are actually quite lacking in biological utility, and may sometimes be opposed to the interests of survival. The existence of such purposes is readily explained by our theory, without inconsistency with the fact there is a powerful average tendency in the biological direction. In particular circumstances, the retroflex and associative mechanisms, following their normal laws of operation, can produce response systems which are of no use under other circumstances. The original circumstances may in some cases be of such rare occurrence that they are never repeated. Sometimes the responses which are established are not actually valuable in the circumstances which create them, because of some artificial or accidental feature of the experience. Thus, if a person happens to be attacked with an organic pain while playing with a dog, he may develop a lasting aversion to this animal, although in fact there was no repeatable connection between the pain and its external circumstances. The cerebral process usually does not penetrate into the actual causal relationships of the factors which it associatively unites. Another source of non-biological purposes lies in the feature of random activity in the cortex, and in the principles of exercise and decay. The principle of exercise or impression may reinforce the consequences of random action in certain cases without reference to retroflexes, while that of decay may produce the effect of inhibition. Random action is a necessary foundation for learning, but will constantly introduce particular neurological and mental factors which have no survival value, or which may be opposed to a successful struggle for existence. These random phenomena are exactly analogous to the "accidental variations" which lie at the foundation of the Darwinian theory. We cannot expect purposes to be any more rigidly determined by biological exigencies than are other factors in the evolutionary situation.
Still another source of deviations from biological utility in human purposes is to be found in the development of social culture or tradition. Social institutions and customs have their original basis in the same processes which operate in individual learning, but they exhibit a much greater fixity, once they have been established. They therefore create a set of conditions to which the individual member of society must adapt himself, as if they were a part of the order of nature. Changing conditions may render such social institutions biologically worthless or even detrimental, but they may still persist as "survivals of culture" for a long time; and continue to coerce the individuals in society. Frequently, in past history, the whims of a single individual or group of individuals have determined such social conditions, particularly in the form of religion. In the days of the Inquisition, it was biologically advantageous for any man to subscribe to the tenets of the Church, although these tenets in turn may have failed to possess any biological significance.