Probabilistic modes of description and explanation first entered into physics in the theory of statistical mechanics. Some aspects of the theory that are of interest to the general philosopher of science are the nature of probability and probabilistic explanations within the theory, the kind of intertheoretical relation displayed between this theory and the nonprobabilistic theory it supplants, and the role to be played in scientific explanations by the invocation of cosmological special initial conditions. In addition, this theory provides the framework for attempts to account for the intuitive sense that time is asymmetric by reference to asymmetric physical processes in time.

History of the Theory

It was in the seventeenth century that thinkers first realized that many material systems were describable by a small number of physical quantities related to one another by simple laws—for example, the ideal gas law, relating...