The author describes the schism between law and science and its reflection of the long-standing tension between two views of human behaviour: free will and determinism; and assesses their relevance in examining crime, consciousness and the notion of involuntary acts. Article by Professor Deborah W. Denno, Fordham University School of Law New York, USA. Published in Amicus Curiae - Journal of the Institute of Advanced Legal Studies and its Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London.