The issue of perhaps greatest concern to historians of science today is the internalist-externalist dichotomy. This volume directly addresses that issue, at the same time providing a context for the serious study of heterodox science and scientific theories. The book consists of four studies, each of which considers the response of a scientific community to an unconventional theory or claim: the acausal physics of Heisenberg; Wegener's geological theory of continental drift; acupuncture; and the statistical argument for extra-sensory perception. As they reveal a wide range of reactions to orthodoxy, the studies themselves exemplify the range of approaches the historian may use in examining scientific unconventionality.