Abstract
Correlation meaning interaction for physical occurrences, the joint probability formalizes this interaction and conceptualizes a stochastic causality. Bayesian reversibility then expresses action-reaction symmetry for spacelike, und cause-effect symmetry for timelike, separations. Information-negeutropy equivalence (that is. reversibility of the twin-faced information concept) extends Mehlberg's “lawlike reversibility” and vindicates Wigner's claim that psychokinesis is reciprocal to gain in knowledge. A covariant axiomatization of probabilities as expressing physical interaction, and displaying the spacetime propagation of information, is proposed. Its correspondence (but essential difference) with the quantum calculation recipe is evidenced. The unfolding paradigm of a twin-faced reality- and- representation universe is stressed, and Pauli's hints in this direction are mentioned