Principles of scienti c method play a considerable role in arguments for scienti c realism and for rival positions. Scienti c realists maintain not only that the aim of science is truth, but that pursuit of science does in fact give rise to truth about observable and unobservable dimensions of reality. Such a realist view has evident implications for the methodology of science. For if the pursuit of science gives rise to truth, it is presumably the methods employed by scientists that are responsible for this achievement. But in this case the use of scienti c methods must lead to truth, that is, they are truth-conducive. Questions of an epistemological nature therefore arise about whether the methods of science are indeed genuinely truth-conducive methods for enquiry.