http://philsci-archive.pitt.edu/archive/00000313/00/engtot.pdf :

"The Second Law made its appearance in physics around 1850, but a half
century later it was already surrounded by so much confusion that the
British Association for the Advancement of Science decided to appoint a
special committee with the task of providing clarity about the meaning
of this law. However, its final report (Bryan 1891) did not settle the
issue. Half a century later, the physicist/philosopher Bridgman still
complained that there are almost as many formulations of the second law
as there have been discussions of it (Bridgman 1941, p. 116). And even
today, the Second Law remains so obscure that it continues to attract
new efforts at clarification. A recent example is the work of Lieb and
Yngvason (1999)."