The theme of this essay is the relation between mental abnormality and criminal responsibility. One particular topic will be the insanity defence, which if successful altogether relieves of responsibility. But I wish to devote my major consideration to the devices which in various jurisdictions have been introduced to permit a verdict which while not eliminating criminal responsibility reduces or diminishes it.

At the present time the full insanity defence is under threat in English-speaking jurisdictions on both sides of the Atlantic, but for different reasons in the different places. When John Hinckley, having shot the President and three other people, was found not guilty by reason of insanity, there was a widespread sense of outrage in the U.S. This has led to changes in the law in many states, all designed to make a plea of insanity less likely to be successful, and some going so far as to eliminate altogether insanity as a separate defence. As a result of what seemed an inappropriate acquittal, reforms have been made which increase the likelihood of the innocent being found guilty.

In England, on the other hand, the insanity defence has become almost obsolete for opposite reasons. A homicide who is mentally ill now very rarely – not more than once or twice a year – will receive a verdict of not guilty by reason of insanity (see Dell, 1986, 30).