Rational scientific inquiry is governed by the rules of scientific method. Adherence to the rules of scientific method warrants the rational acceptance of experimental results and scientific theory. Scientists who accept results or theories licensed by the rules of method do so on a rational basis. This chapter assumes a traditional view of the relation between scientific method and rational justification in science. On such a view, there is a close connection between scientific method and the rational acceptance of scientific theories and experimental results. In particular, compliance by a scientist with the rules of scientific method rationally justifies the scientist's acceptance of a theory or result. The chapter discusses a realist bridge between method and truth. Scientific theories make claims about both observable and unobservable states of affairs. Among the claims which theories make about observable states of affairs are predictions of observable phenomena that are made on the basis of hypotheses about unobservable portions of reality.