MOTIVATION THEORY CLASSIFICATION CENTERS AROUND THE RAPIST'S BASIC MOTIVATIONAL PATTERNS; THIS CATEGORY IS SUBDIVIDED TO INCLUDE THOSE RAPISTS WHOSE ASSAULTS ARE THE EXPLOSIVE EXPRESSIONS OF A PENT-UP SEXUAL IMPULSE; THOSE IN WHOM THE AGGRESSIVE ELEMENT MANIFESTS ITSELF AS A SADISTIC SEXUAL ATTACK; AND THOSE AGGRESSIVE, ANTISOCIAL CRIMINALS WHO ARE OUT TO PILLAGE AND ROB AND FOR WHOM RAPE IS JUST ANOTHER ACT OF PLUNDER. AIM THEORY CLASSIFICATION SUBDIVIDES RAPISTS INTO THOSE WITH AN AGGRESSIVE AIM, THOSE WITH A SEXUAL AIM, AND THOSE WITH SEX-AGGRESSION DIFFUSION. THE FOLLOWING SIX CATEGORIES ARE SUGGESTED UNDER SOCIOBEHAVIORAL CLASSIFICATION SCHEMES: ASSAULTIVE, AMORAL DELINQUENT, DRUNKEN, EXPLOSIVE, DOUBLE-STANDARD, AND OTHERS. BEHAVIOR THEORY CLASSIFICATION PROPOSES OPERATIONAL DEFINITIONS OF RAPIST BEHAVIOR, COVERING RAPISTS WHO LACK ADEQUATE SEXUAL AROUSAL WHEN A RELATIONSHIP IS DEVOID OF AGGRESSIVE SEXUAL CUES, RAPISTS WHO LACK ADEQUATE HETEROSEXUAL SKILLS, AND RAPISTS WHO BECOME EXCESSIVELY AROUSED BY FORCED SEXUAL CONTACT. THREE CATEGORIES UNDER SOCIAL THEORY CLASSIFICATION ARE RAPISTS FOR WHOM THE CRIME IS A SYMPTOM OF AN IDIOSYNCRATIC ACT, EITHER PSYCHOPATHOLOGICAL OR CAUSED BY SPECIAL CIRCUMSTANCES; OFFENDERS FOR WHOM THE CRIME IS MAINLY A 'ROLE-SUPPORTIVE' ACT; AND RAPISTS FOR WHOM THE CRIME IS MAINLY A 'ROLE-EXPRESSIVE' ACT. A CLINICAL CLASSIFICATION SYSTEM DEVELOPED BY THE AUTHOR PRIMARILY FOR USE IN CLINICAL AND LEGAL SETTINGS DISTINGUISHES AMONG PSYCHOTIC, SITUATIONAL STRESS, MASCULINE IDENTITY CONFLICT, SADISTIC, AND SOCIOPATHIC RAPISTS. AT LEAST ONE CASE EXAMPLE IS PRESENTED FOR EACH CLINICAL CATEGORY. REFERENCES ARE PROVIDED. (DAS)