"Professor A. H. Maslow, for example, has conducted a series of researches into extremely healthy people that have led him to conclude that health and optimism are far more positive principles in human psychology than Freud would ever have admitted. Man is a slave to the delusion that he is a passive creature, a creature of circumstance; this is because he makes the mistake of identifying himself with his limited everyday consciousness, and is unaware of the immense forces that lie just beyond the threshold of consciousness. But these forces, although he is unaware of them on a conscious level, are still a far more active influence in his life than any external circumstances. Freudian psychology, for all its achievements, has made a twofold error: it has tried to anatomize the human mind as a pathologist would dissect a corpse, and it has limited its researches to sick human beings. Sick men talk about their illness far more than healthy people talk about their health; in fact, healthy people are usually too absorbed in living to bother with self-revelation. Psychology has consequently been inclined to divide the world into sick people and "normal" people, regarding occasional super-normality as the exception; Maslow has shown that super-normality is a great deal commoner than would be supposed; in fact as common as sub-normality. Ordinarily healthy people often experience a sense of intense life-affirmation (which Maslow calls "peak experiences"); and examination of peak experiences has led Maslow to conclude that the evolutionary drive (which is so clear in art and philosophy) is as basic a part of human psychology as the Freudian libido or the Adlerian will to self-assertion.