In Treatise 2.3.4 Hume provides an explanation of why ‘we naturally desire what is forbid, and take a pleasure in performing actions, merely because they are unlawful’. Hume’s explanation of this phenomenon has barely received any attention so far. But a detailed analysis bears fruit for both Humean scholarship and contemporary moral psychology. After putting the passage in its context, I explain why desiring and taking pleasure in performing certain actions merely because they are unlawful poses a challenge to Hume’s (...) theory of evaluation. Then I propose a solution of the challenge which draws on Hume’s treatment of malice, and highlights the role played by comparison and the self in these apparently paradoxical passions. Finally, I distinguish three views in contemporary discussions of desiring something under the guise of the bad (negationism, parasitism, at-face-valuism), and I argue that Hume’s account stands out as a particularly plausible version of the third view. (shrink)