Scientific explanation has traditionally been regarded as causal explanation. The reaction of positivism against causal explanation was not grounded on the limited range of causality but on the rejection of every sort of explanation, in favor of description. This chapter provides a brief characterization of the logical structure and epistemological import of the explanatory statements of science. Like every exaggeration of logicism, the reduction of explanation to deduction has strange ontological and epistemological consequences. As an illustration of scientific explanation of the first kind consider the case of the recoil undergone by guns upon firing. Science ignores wholly uninterpreted facts; the very selection of facts is guided by theoretical principles and by hypotheses of an explanatory nature. The interpretation of pointer readings is based on theoretical considerations embodied in the very building of the measuring apparatus. Science is both descriptive and explanatory; and description can be distinguished from explanation but not separated from it.