It is argued that the debate over the positivist theory of historical explanation has made only a limited contribution to our understanding of how historians should defend the explanations they propose importantly because both positivists and their critics tacitly accepted two assumptions. The first assumption is that if the positivist analysis of historical explanation is correct, then historians ought to attempt to defend covering laws for each of the explanations they propose. The second is that unless a historian can justify an explanation that he proposes, then his preference for that explanation is not rationally defensible. It is argued that the first assumption is false and that if in order to justify an explanation, one must justify a covering law for it, then the second assumption is also false. A program for investigating how historians should defend their explanations is suggested.