Thermodynamics is a perfect example of a science which is developed from axioms. Unlike classical mechanics, thermodynamics has withstood the quantum revolution without having its foundations shaken. However we will not adhere rigorously to the axiomatic presentation of science from the smallest possible number of axioms. This was achieved by Caratheodory in his proof of the Second Law, but to which we will not bestow  any preference over the Carnot-Clausius proof. The latter derived its concepts from engineering, which is advantageous. Preliminary introduction to statistical mechanics is given with elementary methods.