Sufficient Reasons to Act Wrongly: Making Parfit’s Kantian Contractualist Formula Consistent with Reasons

Research output: Contribution to journalArticle


In On What Matters (2011) Derek Parfit advocates the Kantian Contractualist Formula as one of three supreme moral principles. In important cases, this formula entails that it is wrong for an agent to act in a way that would be partially best. In contrast, Parfit’s wide value-based objective view of reasons entails that the agent often have sufficient reasons to perform such acts. It seems then that agents might have sufficient reasons to act wrongly. In this paper I will argue that such reasons are a symptom of a fundamental inconsistency between the Kantian Contractualist Formula and Parfit’s view of reasons. The formula requires that we consider what everyone could rationally will, while a wide value-based objective view requires that we consider only what the agent has sufficient reasons for doing. The same inconsistency is particularly obvious in Parfit’s version of the Consent Principle, which share important features with the Kantian Contractualist Formula. Parfit accepts that moral principles might entail that we sometimes have sufficient reasons to act wrongly. However, to accept that supreme moral principles have such implications is objectionable if you, like Parfit, also hold that principles with such implications should be rejected or revised. I suggest that we could abandon the requirement that we have to consider the reasons of everyone. This would make the Kantian Contractualist Formula consistent with Parfit’s view of reasons, at least in this respect. I also argue that we can keep most implications of the Kantian Contractualist Formula that Parfit finds attractive.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Philosophy


  • Kantian Contractualist Formula, On What Matters, Parfit D, Reasons, The Consent Principle
Original languageEnglish
Pages (from-to)227-246
Issue number1
Early online date2016 Sep 23
Publication statusPublished - 2017 Mar
Publication categoryResearch