Jump to ContentJump to Main Navigation
The Meaning of 'Ought'Beyond Descriptivism and Expressivism in Metaethics$

Matthew Chrisman

Print publication date: 2015

Print ISBN-13: 9780199363001

Published to Oxford Scholarship Online: October 2015

DOI: 10.1093/acprof:oso/9780199363001.001.0001

Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (www.oxfordscholarship.com). (c) Copyright Oxford University Press, 2017. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a monograph in OSO for personal use (for details see http://www.oxfordscholarship.com/page/privacy-policy). Subscriber: null; date: 24 February 2017

Proposed Semantic Rules for ‘Ought’

Proposed Semantic Rules for ‘Ought’

Source:
The Meaning of 'Ought'
Author(s):

Matthew Chrisman

Publisher:
Oxford University Press

  1. RIa. [ [ ought ] ]c=Ο:For all<xagent,yaction>,[ [ Ο(x,y) ] ]c=1iff the agentx relevant in c has an obligation to perform the actioy relevant in c.

  2. RIb. [ [ ought ] ]c=Ο:For all<xagent,yaction>,[ [ Ο(x,y) ] ]c=1iff the agentxrelevant in c would have a better overall life were she toperform the action y relevant in c.

  3. RIc. [ [ ought ] ]c=Ο:For all<xaction>,[ [ Ο(x,y) ] ]c=1iff xis the mosteffi-cient way to achieve the end most salient in c.

  4. RId. [ [ ought ] ]c=Ο:For all<xoutcome>,[ [ Ο(x) ] ]c=1iffit would be idealin the contextually determined way if x were true.

  5. RIe. [ [ ought ] ]c=Ο:For all<pproposition>,[ [ Ο(p) ] ]c=1iffproposition pislikely true given the body of evidence relevant in c.

  6. RIs.

    1. a. α‎ ought ϕ‎ = 1 iff α‎ is obligated to ϕ‎.

    2. b. α‎ ought ϕ‎ = 1 iff α‎’s life would go better if she ϕ‎ed.

    3. c. ought ϕ‎ = 1 iff ϕ‎ ing is the most efficient way to achieve e.

    4. d. ought x = 1 iff x would be ideal in some way k.

    5. e. ought p = 1 iff p is likely true.

  7. R2. [ [ ought ] ]c=Ο:For all<xsubject,yresponse>,[ [ Ο(x,y) ] ]c=1iff xhas areason to respond with y in the situation made rele-vantinc.

  8. R2'. [ [ ought ] ]c=Ο:For all<xsubject,yresponse>,[ [ Ο(x,y) ] ]c=1iff the sub-ject x relevant in c has a reason to give response ymade relevant in c to the situation made relevant in c.

  9. R2". [ [ ought ] ]c=Ο:For all<xsubject,yresponse>,[ [ Ο(x,y) ] ]c=1iff xhas aconclusive reason to respond with y in the situationmade relevant by c.

  10. R2s. oughtϕ=1 iff αhas conclusive reason to ϕ.

  11. (p.236) R3. [ [ ought ] ]c=Ο:For all<xoption>,[ [ Ο(x) ] ]c=1iffxisthe best optionin the way w determined by c among the set of rele-vant alternatives determined by c.

  12. R3.' [ [ ought ] ]c=Ο:For all<xstate-of-affairs>,[ [ Ο(x) ] ]c=1iffisthe bestimaginable state of affairs in the way w determinedby c among the set of relevant alternatives determinedby c.

  13. R3." [ [ ought ] ]c=Ο:For all<xproposition>,[ [ Ο(x) ] ]c=1iffxis,or is a neces-sary condition on the best possibility in the way de-termined by c among the set of possibilities deter-mined by c.

  14. R3s oughtx=1iffxis highest ranked possible state of affairs amongPc.

  15. R4. [ [ ought ] ]R,x;w=Ο:For all pproposition ,[ [ Ο(p) ] ]w=1 iff[ [ p ] ]w=1in allworlds R-accessible-relative-to-x from w.

  16. R4s oughtp=1iffp=1in all worlds Rc-accessible from w.

  17. R5. [ [ ought ] ]f,g;w=Ο:For all<pproposition>,[ [ Ο(p) ] ]c;w=1iff[ [ p ] ]c;w=1inall worldsνf(w),for which there is no νfsuch thatν<g(w)ν.

  18. R5s oughtp=1iffp=1inall f-worlds for which there are no betterworlds along the g-ordering.

  19. R6. [ [ ought ] ]f,g;w=Ο:For all<pproposition>,[ [ Ο(p) ] ]c;w=1iff[ [ p ] ]c;w=1inall worlds v in some maximal chain cf(w),which are at or above the relevant lower bound B ofthe ordering<g(w).

  20. R6s oughtp=1iff p = 1 in all of the f-worlds, along at least one maxi-mal chain, that are above the relevant lower bound onthe g-ordering.

  21. R7s oughtp=1iff p = 1 in all f-worlds for which there are no betterworlds along the g-ordering, where (a) p may be anynonagentive proposition, or (b) p may be the proposi-tionthat αbringsit about thatq,whereqisany nona-gentive proposition.

  22. (p.237) R8. [ [ ought ] ]f,g;w,α=Ο:For all<Pproposition>,[ [ Ο(πp) ] ]c;w=1iff[ [ p ] ]c;w=1in all world-agent pairsνf(w,α),forwhichthere is noνf(w,α)such thatν<g(w,α)ν.

  23. R8s oughtp=1iffp=1in all world-agent pairs f for which there areno better world-agent pairs along the g-ordering.

  24. R9.

    1. a. [ [ ought ] ]c;w=Οa:For all xagent,yaction ,[ [ Ο(x,y) ] ]c;w=1iff theagent x relevant in c is oughtness related to theaction y relevant in c.

    2. b. [ [ ought ] ]f,g;w=Οb:For all<Pproposition>,[ [ Ο(p) ] ]c;w=1iff [ [ p ] ]c;w=1in all worldsνf(w),for which there is noνfsuch thatν<g(w)ν.

  25. R9s

    1. a. αoughtϕ=1iffαΟaϕ

    2. b. oughtp=1iffp=1at all of the highest w in Pc.

  26. R10. [ [ ought ] ]f,g;w=Ο:For all<pproposition/practition>,[ [ Ο(P) ] ]c;w=1iff[ [ p ] ]c;w=1relative to all of the<w,n>compatible with the back-ground f(w), which are such that there is no <w,n>alsocompatible with the backgroundf(w)and higher rankedbyg(w).

  27. R10s oughtp=1iffp=1at all of the highest<w,n>inPfg.

(p.238)