Hume's proposal of a science of man is often taken as a precursor of the now well-known covering-law model of scientific explanation, sustained by Hempel, Nagel and other contemporary philosophers of science. Among Hume's commentators D. Livingston is an exception, defending the existence of two models of explanation in Hume's epistemology, one suited to the natural sciences and another to the moral ones. Livingston supports his claims in certain passages where Hume allegedly refers to moral causes to explain the motives and reasons of agents involved in phenomena to be explained. Against such interpretation, we here defend that the humean distinction between natural and moral causes is rather of degree than of nature, similar to the one he establishes between proofs and probabilities. Such reading brings Hume's position closer to Nagel's as to classifying sciences according to their different degrees of generality.
Causes and laws; moral causes; covering-laws; unity of science; David Hume; Donald Livingston