Here I discuss three puzzles about practical conditionals and inferences and show how the contextualist semantic framework for "ought" I develop elsewhere (Dowell (ms 1 )) resolves all three puzzles more satisfactorily than any of three prominent rivals, the relativist account of Niko Kolodny and John MacFarlane (2010), the wide-scoping account of John Broome (2004), and the 'trying on' account of James Dreier (2009).The puzzle cases center around the issue of how best to understand indicative conditionals that contain a bare evaluative or normative modal (BNM) in its consequent. A 'bare' modal is one that doesn't contain a clause that makes the relativization of the modal explicit (as in "given the circumstances, the Doctor morally ought to prescribe nothing"). On the semantics for modals canonical among linguists, bare modals get the values for their relativizations as a function of the context of utterance. This makes room for the hypothesis that the puzzles arise as a result of some form of equivocation. This is just what I'll argue below.The plan of action is as follows: First I'll introduce the puzzle cases and six desiderata for their solutions, briefly sketch the semantic accounts of 'ought' and 'if' I favor, and then show how only the contextualist semantics for modals defended here and elsewhere 2 is able to resolve each while satisfying all six desiderata.
The Puzzles
First Puzzle: Odious Inferences1 A special thanks to Aaron Bronfman, for exceptionally careful comments on an earlier draft of this paper, and to Jamie Dreier, for extensive discussion. Thanks also to Fabrizio Cariani for comments on an earlier draft and to John Broome, Matthew Chrisman, Patricia Greenspan, Alex Silk, David Sobel, and participants in the 7 th Annual Madison Metaethics Workshop for discussion. 2 See Dowell (ms 1 ), (ms 2 ), and (forthcoming).
2Consider two cases involving practical inferences, the first, unusual and the subject of much philosophical discussion and controversy, the second, completely mundane.
MURDER:M1. You want to murder messily.M2. If you want to murder messily, you ought to use a chainsaw. 3 M3. Therefore, you ought to murder with a chainsaw.MURDER is puzzling. Many report their inclination to regard both premises as true, but the conclusion false. But, how can that be? The sentences appear to have the structure of ordinary, modus ponens reasoning, so the truth of the premises should suffice for the truth of the conclusion. John Broome has suggested that we explain our acceptance of the premises, but rejection the conclusion in inferences like MURDER by giving the modal in its second premise wide-scope and interpreting the conditional as a material conditional. 4 (Here I'll use "widescoping" to describe this strategy of giving the modal wide-scope and treating the conditional as the material conditional.) If we do that, the conclusion won't follow from the truth of the premises, since, despite appearances, the argument doesn't in fact have a modus ponens structure. If Broome's proposal is right, the poi...