Let me set the second law problem in a different way. First a few negative views: Bridgman's states in 1941 that "there are almost as many formulations of the second law as there have been discussions of it". In a similar spirit, Von Neumann suggests that whoever uses the term "entropy" in a discussion always wins: "...no one knows what entropy really is, so in a debate you will always have the advantage". Truesdell goes even further - he says about the second law: "A century of philosophers and journalists have acclaimed this commandment; a century of mathematicians have shuddered and averted their eyes from the unclean".

Curiously, the second law's fist version (the Carnot theorem) was quite normal:

Carnot theorem: All reversible machines working between two given temperatures have the same efficiency.

We can compare this with other laws stated in similar terms:

Newton's second law: All bodies having the same mass and experiencing the same force, have the same acceleration.
Fick's second law: For a given solvent, all solutes moving down concentration gradients with the same curvature (second derivative of concentration with respect to distance) have the same rate of increase in concentration.

Why has the second law of thermodynamics undergone the development leading to the statements of Bridgman, Von Neumann and Truesdell? Newton's second law and Fick's second law obviously did not undergo the same development - why?

Pentcho