The sexual offender has intense castration anxiety, a mother who is engulfing, a father who is distant or punitive, and an actual seductive, often incestuous experience in childhood. This background is linked by the author with the tendency of the offender to be concrete in his thinking and direct in action rather than satisfied by fantasy. This leads to disillusionment in the ego ideal and a feeling of exemption from ordinary rules of conduct. The taboo experience is substituted for a taboo object in perversion formation. Two case histories and several brief clinical examples are presented.