The Lucretian swerve: the biological basis of human behavior and the criminal justice system.

It is widely believed, at least in scientific circles, that living systems, including mankind, obey the natural physical laws. However, it is also commonly accepted that man has the capacity to make "free" conscious decisions that do not simply reflect the chemical makeup of the individual at the time of decision--this chemical makeup reflecting both the genetic and environmental history and a degree of stochasticism. Whereas philosophers have discussed for centuries the apparent lack of a causal component for free will, many biologists still seem to be remarkably at ease with this notion of free will; and furthermore, our judicial system is based on such a belief. It is the author's contention that a belief in free will is nothing other than a continuing belief in vitalism--something biologists proudly believe they discarded well over 100 years ago.