Joule’s Energy Conservation Law was the first “meta-law”: a general principle that all physical equations must satisfy. It has led to many important and useful physical discoveries. However, a recent analysis seems to indicate that this meta-law is inconsistent with other principles—such as the existence of free will. We show that this conclusion about inconsistency is based on a seemingly reasonable—but simplified—analysis of the situation. We also show that a more detailed mathematical and physical analysis of the situation reveals that (...) not only Joule’s principle remains true—it is actually strengthened: it is no longer a principle that all physical theories should satisfy—it is a principle that all physical theories do satisfy. (shrink)