Role within programme and connections to other courses. This course builds from the bottom up (molecules → continuous phases) what Thermal Physics describes from the top down (macroscopic properties → kinetic theory). We reinforce the idea (from Quantum Physics and Quantum Mechanics I) that our macroscopic observations can be based on underlying probabilities, rather than strict determinism. Content. The ensemble basis for basic statistics, equilibrium between interacting systems, the Laws of Thermodynamics (from a microscopic standpoint), classical and quantum statistical distributions, applications of Maxwell-Boltzmann statistics, kinetic theory of gases revisited, applications of quantum statistics.