He treats thermodynamics like geometry or classical mechanics. You don't prove postulates; you accept them because they match reality. This approach strips away the historical baggage and reveals the pure logical skeleton of the theory.

But if you persist, you will never see thermodynamics the same way again. You will stop seeing a collection of random equations and start seeing a .

The most famous of these is the : There exists a function (the entropy) whose maximization governs equilibrium.