No new miracles, same old tricks

Laudan (1984) distinguishes between two senses of success for scientific theories: (i) that a particular theory is successful, and (ii) that the methods for picking out approximately true theories are successful. These two senses of success are reflected in two different ways that the no miracles argument for scientific realism (NMA) may be set out. First, I set out a (traditional) version of NMA that considers the success of particular theories. I then consider a more recent formulation of NMA (Psillos, 1999). This version of NMA is aimed at making us believe that our methods for picking out approximately true theories are reliable. I shall argue that the success of the latter argument is dependent on the success of the first. Therefore, even though Psillos presents a new formulation of NMA, the evidential support for it is no stronger than the evidential support for the original version.