The Correspondence Principle, Formal Analogy, and Scientific Rationality

This paper offers a case study in philosophical history of quantum theory, focusing on the role of Bohr's correspondence principle in the creation of the new mechanics. I argue that the principle is best understood as formal or symbolic analogy in the strictly Kantian sense of analogy. By showing how new quantum formalism embodies this philosophically loaded principle, I claim that the emergence of the new mechanics is unintelligible unless we take into account Bohr's Kantian philosophy before 1925. This may shed fresh light on the problem of scientific rationality. In so far as the philosophy of science draws on the history of science, and forms its picture of the bona fides and rationality of science on that basis, then if the history is seriously misguided, so too will be the philosophy 'modelled' on it. (Sharrock and Read 2002, p. 11, original emphasis).