Often creationists appeal to the second law of thermodynamics to show that evolution could never have happened in the way commonly alleged. Usually the second law is thought of in such arguments in terms of statistical mechanics, or of information theory. The author uses the law in its original macroscopic form, which entails nothing at all about any microscopic structure of things, to reach the same conclusion: that the alleged evolution is impossible. There may be certain advantages to the macroscopic formulation: for instance, it may leave less opportunity for quibbles about open and closed systems.