The actual discussion on brain research, free will, and legal responsibility repeats all the arguments of a very similar discussion in central Europe 100 years ago, around 1900. Already back then the idea that human perception, emotions, thinking and behavior have a material basis was not new. It is conditioned and limited by the structure and workings of the brain. This applies to sane and sick brains alike. In this debate criminality was made a topic of biology by interpreting it as a symptom of genetic “degeneration”. In regard to brain damage in humans with socially deviant behavior, psychiatry claimed responsibility for a large proportion of criminals. This article lays out some important positions of psychiatry and jurisprudence in this debate on the foundations of legal responsibility and their impact up to now. The debate leads to the conclusion that human behavior cannot be described adequately in physical terms of cause and effect. The psychological approach to describe reasons, motives and intentions is substantially more appropriate. This method is also accepted by criminal law. Copyright © 2007 John Wiley & Sons, Ltd.