The very general occurrence of the homosexual in ancient Greece, and its wide occurrence today in some cultures in which such activity is not taboo s… - Alfred Kinsey

There is an honesty in science which demands that the best means be used for the determination of truth. Certainly there are many sorts of truth in the universe, and many aspects of truth must be taken into account if man is to live most effectively in the social organization to which he belongs. But in regard to matter---the stuff of which both non-living materials and living organisms are made---scientists believe that there is no better way of obtaining information than that provided by human sense organs. No theory, no philosophy, no body of theology, no political expediency, no wishful thinking, can provide a satisfactory substitute for the observation of material objects and of the way in which they behave. (page 9).

Males do not represent two discrete populations, heterosexual and homosexual. The world is not to be divided into sheep and goats. Not all things are black nor all things white. It is a fundamental of taxonomy that nature rarely deals with discrete categories. Only the human mind invents categories and tries to force facts into separated pigeon-holes. The living world is a continuum in each and every one of its aspects. The sooner we learn this concerning human sexual behavior, the sooner we shall reach a sound understanding of the realities of sex.

The impression that infra-human mammals more or less confine themselves to heterosexual activities is a distortion of the fact which appears to have originated in a man-made philosophy, rather than in specific observations of mammalian behavior. Biologists and psychologists who have accepted the doctrine that the only natural function of sex is reproduction, have simply ignored the existence of sexual activity which is not reproductive. They have assumed that heterosexual responses are a part of an animal's innate, "instinctive" equipment, and that all other types of sexual activity represent "perversions" of the "normal instincts". Such interpretations are, however, mystical. They do not originate in our knowledge of the physiology of sexual response (Chapter 15), and can be maintained only if one assumes that sexual function is in some fashion divorced from the physiologic processes which control other functions of the animal body.