The principle of alternate possibilities and 'ought' implies 'can'

Abstract

This article is primarily a response to Gideon Yaffe (Analysis, 1999), who attacked David Widerker’s argument (Analysis, 1991) that Harry Frankfurt’s position (JP, 1969) that one can be blameworthy for doing something that one could not avoid doing commits him to rejecting the principle that ‘ought’ implies ‘can’ (OIC). I argue that Yaffe misrepresents Widerker’s argument, making two unjustified assumptions: (1) that Widerker requires the premise that one is blameworthy for doing something only if one could have done something else instead, and (2) that OIC is acceptable only for acts, not for omissions. I also discuss Alex Blum’s claim (Analysis, 2000) that cases of kleptomania provide counterexamples to OIC, arguing that the issue requires further discussion.