Abstract: Hypothetical imperatives are problematic: does ‘If you want to get drunk every evening, you ought to work in a bar’ entail, given ‘You want to get drunk every evening’, ‘You ought to work in a bar’? What of the inference from ‘Given that you are going to stab him, you ought to stab him with the shorter knife’, and ‘You are going to stab him’, to ‘You ought to stab him with the shorter knife’? One might cite Broome's ‘normative requirements’ supposedly governing thinking, which are not subject to such detachment. Doubts may be entertained about both the content, and the role, of these requirements. Their logic needs scrutiny, in respect of detachment and contraposition. So long as the concluding ‘ought’ is relative to the circumstance stated in the second premise, it may be allowed to follow, even if one has no reason to act upon it.

Keywords: ought, hypothetical imperatives, normative requirements, detachment, contraposition,