The dilemmas are: 1) difficulty in establishing causal linkages; 2) problems associated with the legal status of substances; 3) ecological and individualistic fallacies; 4) measurement issues and problems with data sources; and 5) research design problems. Most people agree that substance use provides a provocative context for violence, but a direct relation has hardly been defined. Although most violent events involve substance use among offenders and victims, most substance use occurs among persons who are not violent. Besides chemical reactions, research must take into account individual factors and social context. Sometimes, persons use substances as an excuse for committing violent acts, or, with violent intentions already, as a means to achieve an emotional state to carry out violent acts. Social context indicates the situational ecology that regulates aggression and the arousal processes that motivate it. 44 references