MANY people regard the physiological approach to the study of Personality with distaste, because to them it seems that it is entirely materialistic, and forbids any looking forward or any purpose in life. It would seem quite certain that some sort of spiritual outlook is essentially a human characteristic, and is inevitable, once selfconsciousness and reflective thought have “emerged as new entities in the march of evolution. Moreover, some sort of philosophy of life is absolutely necessary, if the personality is to be properly organized and enabled to get through life. One of the most characteristic features of the maladapted neurotic is that he is not provided, in many cases, with an adequate philosophy of life. The phrase philosophy of life is used in preference to religion, because a religion may be professed by certain people, without their acquiring thereby any adequate working scheme to afford them an explanation of their true relationship with the environment and with the universe as a whole. This is not to say that religion in its various forms does not serve many personalities as a perfectly adequate, and indeed, for them, the only possible philosophy. The purpose of this chapter must be therefore to inquire whether the personality, as sketched out, can have a spiritual aspect, and whether, from a psycho-physical standpoint, an adequate philosophy of life is conceivable. It must be understood that such a function of the personality is only possible at the highest level of evolution so far reached. Clearly, one of the chief functions which characterizes advance in mental power, is that of distinguishing the self from the environment. The development of this function can be observed in the young infant, who, at first, has no consciousness beyond the satisfaction of his various organic needs, and cannot distinguish his hands or feet from the objects around him.