This monograph constructs classical statistical mechanics as a deductive system, based on the equations of motion and the basic postulates of probability. The treatment consists chiefly of theorems and proofs that are expressed in a manner that reveals the theory's logical structure. Requiring only familiarity with the elements of calculus and analytical geometry, is geared toward advanced undergraduates and graduate students in mathematical physics. An opening chapter on mathematical tools makes the text as self-contained as possible. Subsequent chapters explore the phase flows of mechanical systems, the initial distribution of probability in the phase space, and both time-dependent and time-independent probability distributions. A final chapter covers statistical thermodynamics.