Global versus local arguments for scientific realism

There has been considerable recent discussion over whether the scientific realist should primarily take a local or a more global approach. A global approach is to argue for scientific realism as a general claim by taking account of the overall reliability of scientific method, as in the traditional No Miracles argument. An alternative is the local approach, which is to argue for the existence of particular entities case by case on the basis of the scientific evidence. For example, localists have suggested that the realist should argue for the existence of atoms using evidence such as that provided by Perrin’s early-20th-century experiments on Brownian motion. Considering this case leads to the conclusion that although localists can address some kinds of anti-realist concerns, there are certain anti-realist challenges which localists can only meet at the expense of weakening their own positive arguments.