Part of a five-audiocassette series containing the proceedings of the 1977 statewide Criminal Law Seminar, sponsored by the California Attorneys for Criminal Justice, and primarily intended for an audience of defense attorneys and law students, this presentation offers arguments in favor of the diminished mental capacity of defendants in murder cases. Since the legal definition of diminished capacity is still tentative and confusing, the opinions of forensic psychiatrists in favor of the diminished capacity are cited in homicide cases. Several diminished capacity cases are cited to encourage defense lawyers to analyze the personalities and life histories of their clients, in order to find out why they committed a violent crime (e.g., whether the motive was hunger, emotional instability, surrounding circumstances, or inordinate fear for one's life) that prompted them to commit the crime for which they are on trial. A total and complete defense can be built upon sufficient evidence that a client acted in a state of unconsciousness (here meaning a state of altered consciousness, or amnesia caused by shock or emotional trauma, irresistible impulse, intoxication, or intolerable provocation. The corresponding section of the syllabus provided with this cassette series contains case citations, legal definitions, and other instructional material on diminished capacity and altered states of consciousness from different sources.