Section 2 of the 1957 Homicide Act is indefensible: the concept of 'mental responsibility' is a hybrid which turns the psychiatrist witness either into a thirteenth juryman or a spare barrister. But reform does not lie along the lines suggested by the Butler Committee or the Criminal Law Revision Committee. The latter leaves the jury with insufficient guidance; the former returns to the bad eighteenth century policy of treating mental illness not as a factor in determining responsibility but as a (...) status exempting from responsibility. The much criticised McNaughton rules provide a sounder basis for deciding where responsibility should be assigned in criminal cases. (shrink)