"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."

“With the right of the scientist to investigate most aspects of the material universe, most persons will agree; but there are some who have questioned the applicability of scientific methods to an investigation of human sexual behavior....It is as though the dietician and biochemist were denied the right to analyze foods and the processes of nutrition, because the cooking and proper serving of food may be rated a fine art, and because the eating of certain foods has been considered a matter for religious regulation. .”

“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. .”

“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 suggests that the capacity of an individual to respond erotically to any sort of stimulus, whether it is provided by another person of the same or opposite sex, is basic in the species.”

“At the risk of being repetitious, I would remind the group that we have found the highest frequency of induced abortion in the group which, in general, most frequently uses contraceptives.”

“The history of medicine proves that in so far as man seeks to know himself and face his whole nature, he has become free from bewildered fear, despondent shame, or arrant hypocrisy. As long as sex is dealt with in the current confusion of ignorance and sophistication, denial and indulgence, suppression and stimulation, punishment and exploitation, secrecy and display, it will be associated with a duplicity and indecency that lead neither to intellectual honesty nor human dignity.”

“The inherent physiologic capacity of an animal to respond to any sufficient stimulus seems, then, the basic explanation of the fact that some individuals respond to stimuli originating in other individuals of their own sex-and it appears to indicate that every individual could so respond if the opportunity offered and one were not conditioned against making such responses. There is no need of hypothesizing peculiar hormonal factors that make certain individuals especially liable to engage in homosexual activity, and we know of no data which prove the existence of hormonal factors . There are no sufficient data to show that specific hereditary factors are involved. Theories of childhood attachments to one or the other parent, theories of fixation at some infantile level of sexual development, interpretations of homosexuality as neurotic or psychopathic behavior or moral degeneracy, and other philosophic interpretations are not supported by scientific research, and are contrary to the specific data on our series of female and male histories.”