 On Jammer’s view, Bohr’s claim that the correspondence principle is a law is simply an attempt to cover up the inconsistent foundations of the old quantum theory. In opposition to Bohr’s claim that quantum theory is a rational generalization of classical mechanics, Jammer interprets Bohr as viewing quantum and classical mechanics as irreconcilable, and hence interprets the correspondence principle as only a “formal analogy of heuristic value.” At the end of his discussion of the correspondence principle, Jammer concludes “his [Bohr’s] numerous and often somewhat conflicting statements, made from 1920 to 1961, on the essence of the correspondence principle make it difficult, if not impossible, to ascribe to Bohr a clear-cut unvarying conception of the principle” (Jammer 1966, p. 117).