Data compiled to increase understanding of the insanity defense and insanity defendants documents that this defense is rarely used and plays a minor role in the criminal justice system. However, it must be retained in Western jurisprudence to uphold the moral integrity of the law. The Commission offers 11 specific recommendations that preserve and strengthen the workings and public understanding of the insanity defense. These call for retention of the insanity defense (with the burden of proof on the defendant to prove that defense by a preponderance of the evidence), rejection of the alternative verdict of 'guilty but mentally ill,' and the addition of a strong dispositional provision to provide additional safeguards for the community. Recommendations also urge adoption of the term 'not responsible by reason of insanity' instead of 'not guilty by reason of insanity,' suggest that mental health experts in proceedings involving the insanity defense not be permitted to testify on the ultimate legal issues, and support the appropriation of necessary funds for adequate mental health care of those convicted of crimes as well as those acquitted by reason of insanity. The history of the insanity defense and myths and realities surrounding this defense are examined. Footnotes are included. An appendix lists members of the National Commission on the Insanity Defense.