Foundations of the State Principle

Abstract

The state principle is an important and fundamental thermodynamic concept. Having only recently been formally stated, however, there is still some disagreement as to the basis of the principle’s derivation. An examination of various state principle presentations leads to the conclusion that the state principle must be based on the first and second laws, and, additionally, that the energy, the amounts of the constituents, and the parameters solely determine property. Microscopic properties and non-equilibrium states are not inherently governed by the state principle, but extensions have been formulated to incorporate these areas.