Hume's Fork, and his Theory of Relations[Note 1. For discussion of this paper, I am very grateful ...]

Hume’s Fork—the distinction between“relations and ideas”and“matters of fact”intro-duced in hisfirstEnquiry—is well known, though considered by most specialist scholarsto be a crude simplification of the far more sophisticated theory of relations in hisTrea-tise. But close analysis of theTreatisetheory shows it to be an unsatisfactory reworkingof Locke’s taxonomy, implausibly identifying relations with mental operations and deliv-ering a confused criterion of demonstrability which Hume subsequently abandons infavour of his Conceivability Principle. The latter then becomes the basis for Hume’sFork, the theory of which, as implicitly defined by the various criteria he specifies, turnsout to be consistent and plausible. However it faces a number of potential problems,some of which Hume might have been expected to address, while others—particularlyconcerning his tendency to identify apriority, demonstrability, and necessity—derive fromrelatively recent Epistemology, Philosophy of Language, and Philosophy of Mathematics.All of these are considered, some requiring tightening of Hume’s distinction while othersimply limitations. Finally, a conclusion is drawn emphasising the continuing value ofHume’s position, despite these difficulties.