The only unnatural sex act is that which you cannot perform.

The heterosexuality or homosexuality of many individuals is not an all-or-none proposition.

The male's difficulties in his sexual relations after marriage include a lack of facility, of ease, or of suavity in establishing rapport in a sexual situation.

We are the recorders and reporters of facts - not the judges of the behaviors we describe.

There is a tendency to consider anything in human behavior that is unusual, not well known, or not well understood, as neurotic, psychopathic, immature, perverse, or the expression of some other sort of psychologic disturbance.

Cheese crumbs spread before a pair of copulating rats will distract the female but not the male.

Only the human mind invents categories and tries to force facts into separated pigeonholes.

Few males achieve any real freedom in their sexual relations even with their wives. Few males realise how badly inhibited they are on these matters.

Art alone develops weaklings, science alone, monsters. Somewhere, somehow, we must combine the two.

Males do not represent two discrete populations, heterosexual and homosexual. The world is not to be divided into sheeps and goats. Not all things are black nor all things white.

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.

The range of variation in the female far exceeds the range of variation in the male.