Clausius’ thermodynamics, the logical conclusion of the conceptual differentiation of caloric in terms of the two laws of thermodynamics

Thermodynamics is the theory of energy resulted from the conceptual differentiation of caloric, circa 1850-1865, into energy, entropy, and heat (a disorganized form of energy) in terms of the two laws of thermodynamics, the first law and the second law. The theory is often referred to as the Clausius-Kelvin theory as a single theoretical system. In actual fact, it is a blend of Kelvin’s contribution and Clausius’ contribution. Orthodox engineering thermodynamics is instead an update of the energy physics formulated by Kelvin circa 1850-55 based on the _energy premise_, which stops short of the conceptual differentiation in the exact sense. It is the Clausius version of the theory that was transformed by Gibbs into Gibbsian thermodynamics, which is the result of the conceptual differentiation. As a result, engineering thermodynamics is a defective theoretical system while Gibbsian thermodynamics is a successful one. This paper makes the case that Clausius’ theorem of entropy can be developed for reforming engineering thermodynamics into a coherent system by rejecting the energy premise.