Post-Mechanical Explanation in the Natural and Moral Sciences: The Language of Nature and Human Nature in David Hume and William Cullen
Abstract
It is common wisdom in intellectual history that eighteenth-century science of man evolved under the aegis of Newton. It is also frequently suggested that David Hume, one of the most influential practitioners of this kind of inquiry, aspired to be the Newton of the moral sciences. Usually this goes hand in hand with a more or less explicit reading of Hume’s theory of human nature as written in an idiom of particulate inert matter and active forces acting on it, i.e. essentially that of Newton’s Principia. Hume’s outlook on the mental world is thus frequently described in terms of conceptual atoms whose association is compared to interparticulate attractions analogous with Newtonian forces in general, and gravity in particular. In the present paper I argue that Hume’s theory can indeed be understood in Newton’s wake, but not in the context of the Principa’s reception but that of the Opticks, which exerted a more significant influence on natural inquiry in eighteenth-century Scotland. I intend to show that Hume speaks a language and represents an outlook on human matters convergent with “philosophical chemistry” in Scotland at that time, and particularly to his later friend and physician William Cullen.