Thinking About the Ultimate Argument for Realism

Alan Musgrave has been one of the most passionate defenders of scientific realism. Most of his papers in this area are, by now, classics. The title of my paper alludes to Musgrave’s piece “The Ultimate Argument for Realism”, though the expression is Bas van Fraassen’s (1980, 39), and the argument is Hilary Putnam’s (1975, 73): realism “is the only philosophy of science that does not make the success of science a miracle”. Hence, the code-name ‘no-miracles’ argument (henceforth, NMA). In fact, NMA has quite a history and a variety of formulations. I have documented all this in my (1999, chapter 4). But, no matter how exactly the argument is formulated, its thrust is that the success of scientific theories lends credence to the following two theses: a) that scientific theories should be interpreted realistically and b) that, so interpreted, these theories are approximately true. The original authors of the argument, however, did not put an extra stress on novel predictions, which, as Musgrave (1988) makes plain, is the litmus test for the ability of any approach to science to explain the success of science. Here is why reference to novel predictions is crucial. Realistically understood, theories entail too many novel claims, most of them about unobservables (e.g., that