Liberties in Nature. On Photons, Bugs and Chess Players

Free will is an old philosophical enigma that has been recently revived by neuropsychology. We restrict ourselves to the problem that determinism seems to allow only an illusion of freedom but random decissions do not contain any freedom either. We show that this is a problem of natural sciences, not philosophy. Physics motivates replacing determinism by the principle of weak causality and introducing the concept of liberty. Its empirical basis remains untouched, but the theoretical interpretations of the state space in Newton theory and of the space-time in general relativity are changed. The emerging understanding of time agrees with the idea suggested once by Popper. In biology, the most important liberties are those of mutation, of motion and of the portable neural representation. We distinguish freedom and liberty. Each freedom is associated with some liberty and is defined as the ability to perform three processes called realization, selection and use of memory. This makes freedom accessible to experimental study. The freedom of will is explained by giving account of the underlying specific liberty and processes. While the realization has an ample space for randomness, the selection is mostly causal. Thus, determinism can be rejected without forcing decissions to be random. The experiments of Libet and the role of consciousness are discussed.