'Must', 'Ought' and the Structure of Standards

This paper concerns the semantic difference between strong and weak necessity modals. First we identify a number of explananda: their well-known intuitive difference in strength between ‘must’ and ‘ought’ as well as differences in connections to probabilistic considerations and acts of requiring and recommending. Here we argue that important extant analyses of the semantic differences, though tailored to account for some of these aspects, fail to account for all. We proceed to suggest that the difference between ’ought’ and ’must’ lies in how they relate to scalar and binary standards. Briefly put, must(ϕ) says that among the relevant alternatives, ϕ is selected by the relevant binary standard, whereas ought(ϕ) says that among the relevant alternatives, ϕ is selected by the relevant scale. Given independently plausible assumptions about how standards are provided by context, this explains the relevant differences discussed.

[1]  Justin Snedegar,et al.  Reason claims and contrastivism about reasons , 2013 .

[2]  Jaakko Hintikka,et al.  Time And Modality , 1958 .

[3]  A. Kratzer.  The Notional Category of Modality , 2008 .

[4]  Daniel Lassiter.  Measurement and Modality: The Scalar Basis of Modal Semantics. , 2011 .

[5]  Alex Silk,et al.  Modality, Weights, and Inconsistent Premise Sets , 2012 .

[6]  Aynat Rubinstein,et al.  Figuring out what we ought to do: the challenge of delineating priorities , 2013 .

[7]  Kai von Fintel,et al.  How to Say Ought in Foreign: The Composition of Weak Necessity Modals , 2008 .

[8]  Paul Portner,et al.  Ordering combination for modal comparison , 2012 .

[9]  Stephen Finlay,et al.  Oughts and ends , 2009 .

[10]  Aynat Rubinstein,et al.  Roots of modality , 2012 .

[11]  Angelika Kratzer,et al.  What ‘must’ and ‘can’ must and can mean , 1977 .

[12]  Fabrizio Cariani,et al.  'Ought' and Resolution Semantics. , 2013 .

[13]  V. Hacquard.  Aspects of modality , 2006 .

[14]  K. Fintel,et al.  What to Do If You Want to Go to Harlem: Anankastic Conditionals and Related Matters∗ , 2005 .

[15]  P. Portner.  Imperatives and modals , 2007 .

[16]  Stephen Finlay,et al.  Confusion of Tongues: A Theory of Normative Language By Stephen Finlay , 2014, Analysis.

[17]  Hector-Neri Castañeda,et al.  ‘Ought’ and ‘Better’ , 1973 .

[18]  Stephen Finlay,et al.  What ought probably means, and why you can’t detach it , 2010, Synthese.

[19]  Aaron Sloman,et al.  IV.—‘OUGHT’ AND ‘BETTER’ , 1970 .

[20]  Andrew J. I. Jones,et al.  ‘Ought’ and ‘Must’ , 2004, Synthese.