The opening chapter reviews the historical background of concepts underlying current legal tests for insanity, and it is concluded that the tests and the meanings underlying the tests are necessarily subject to change in response to the changing concepts of the behavioral sciences. The second paper discusses the substance and application of the Canadian criminal code bearing upon the insanity defense and its relevance to irresistible impulse, automatism, and mental disorder not conforming to the legal definition of insanity. Another chapter notes that legal culpability based upon the degree of criminal responsibility determined in each case will inevitably be influenced by the psychiatric, social, and moral concepts of responsibility prevalent in a society at a given time, and the Canadian legal concepts bearing upon the effects of drunkenness upon criminal responsibility are considered in the subsequent chapter. Other papers consider modern neurology and psychiatry and the problem of criminal responsibility; psychiatrists, lawyers, and the adversarial system; in defense of the insanity defense; the long-term management of the mentally disordered offender; the post-release adjustment of men found not guilty by reason of insanity; and responsibility and madness in Dostoevsky's 'Crime and Punishment.' Chapter notes and references are provided.