ABSTRACT
This chapter argues that all theoretical representation must proceed via the use of a perceptible model. Theoretical-explanatory posits are represented by specifying the determinate ways that such entities both resemble and differ from some previously-experienced phenomena. Hume repeatedly rejects as specious and chimerical those posits of his predecessors that cannot be so represented. The chapter explains that Hume reject the notion of necessary connection on the grounds that there is no experience that can serve as the model for such an idea. Hume endorses and employs substantial explanation as the proper methodology for the science of human nature. Some philosophers take the very purpose of substantial explanation to be to represent the necessary connections among distinct existences, so if Hume rejects that thesis, then one can legitimately ask what he takes its aim to be. The chapter explicates the nature of substantial explanation sans the idea of necessary connection.
