Sigmund Freud,
Three Contributions to the Theory of Sex
“ Experience teaches that among the latter no disturbances of the sexual impulse can be found other than those observed among the sane, or among whole races and classes. Thus we find with gruesome frequency sexual abuse of children by teachers and servants merely because they have the best opportunities for it. The insane present the aforesaid aberration only in a somewhat intensified form; or what is of special significance is the fact that the aberration becomes exclusive and takes the place of the normal sexual gratification. ”
