Prescription, Description, and Hume's Experimental Method

There seems a potential tension between Hume's naturalistic project and his normative ambitions. Hume adopts what I call a methodological naturalism: that is, the methodology of providing explanations for various phenomena based on natural properties and causes. This methodology takes the form of introducing 'the experimental method of reasoning into moral subjects', as stated in the subtitle of the Treatise; this 'experimental method' seems a paradigmatically descriptive one, and it remains unclear how Hume derives genuinely normative prescriptions from this methodology. In resolving this problem, I will argue that Hume's naturalistic methodology - that is, his 'experimental philosophy' (THN Intro 7), or what has come to be known as his experimental method - consists of the systematization of phenomena pertaining to human nature. In applying his experimental method to normative subjects, Hume systematizes our normative judgements, deriving general principles of normative justification; he then reflexively applies these principles to the pre-philosophical judgements from which they derive, dismissing and/or correcting those that do not accord with his systematized account.