In Germany, a perpetrator had to be of sound mind to be convicted of a crime throughout the nineteenth and twentieth centuries. The criminal code was clear, but reality was not. From the moment that physicians accepted alcoholism and drug addiction as diseases of mind and body, the question of what to do with alcoholic and addicted criminals troubled legal theorists. How were judges to maintain the balance of justice if, on the one hand, a potential perpetrator chose to be of unsound mind by drinking or using drugs, but on the other, he was sick, unable to control his actions? As this article demonstrates, the legal system was lenient towards inebriated perpetrators as a by-product of the insistence of German doctors that alcoholism and addiction were diseases.