There is no reason and no constitutional justification for limiting the insanity defense to those who have suffered from a diagnosable mental disease or defect. Mens rea, or criminal intent, would not only be a more accurate description of the defense, but would also provide a more narrower or stricter definition of the 'insanity' defense, making it less likely for offenders to successfully feign 'insanity.' Although the Supreme Court has never articulated a general constitutional doctrine of mens rea, the Court has clearly indicated that mens rea is a constitutionally required element of all offenses defined as criminal. Due to mental instability a person can 'intentionally' commit homicide and still lack mens rea, as is the case with the individual who plans and commits a murder--with intent to kill and with awareness of the consequences of his acts--in accordance with instructions from God. Through the application of mens rea to the insanity defense, the psychiatric witness would not have to determine such ambiguous issues as whether or not a defendant's crime was the 'product' of a mental illness (the Durham rule), whether or not the defendant could 'appreciate' the wrongfulness of the conduct, or whether the defendant was substantially unable to conform conduct to the requirements of the law. In addition, with appropriate modification in the provisions to waive 5th amendment rights, defendants should be able to present nonpsychiatric exculpatory mental-state evidence without having to testify against themselves. Finally, a strict insanity test would mean that offenders who are seriously disturbed but not wholly lacking in mens rea would not automatically be confined to civil mental hospitals. To the extent that sentencing discretion is abolished, the judiciary will lose the flexibility that is required to deal with mentally disturbed offenders as humanely and intelligently as possible. The New York State Morgenthau Commission's proposal for legislative maxium penalties would establish guidelines (emphasizing the severity of offense and the defendant's prior criminal history) that would indicate what the sentence the judge should hand down, even freeing the judge to depart from the guidelines in unusual circumstances. Thus, under this proposal, judges would be free to depart from the guidelines when an offender's criminal behavior was apparently the result of a severe or acute psychological disturbance and when an 'unusual' sentence would best serve to rehabilitate the defendant while still protecting the community. Twenty-two references are appended.