“Ought implies Can”: secondary and higher-order interpretations

Transforming structures by set interpretations

We consider a new kind of interpretation over relational structures: finite sets interpretations. Those interpretations are defined by weak monadic second-order (WMSO) formulas with free set variables. They transform a given structure into a structure with a domain consisting of finite sets of elements of the orignal structure. The definition of these interpretations directly implies that they ...

More on “Ought” Implies “Can” and the Principle of Alternate Possibilities

Inability and Obligation in Moral Judgment

It is often thought that judgments about what we ought to do are limited by judgments about what we can do, or that "ought implies can." We conducted eight experiments to test the link between a range of moral requirements and abilities in ordinary moral evaluations. Moral obligations were repeatedly attributed in tandem with inability, regardless of the type (Experiments 1-3), temporal duratio...

‘Ought’ implies ‘can’ and the principle of alternate possibilities

In his paper ‘What we are morally responsible for’,1 Harry Frankfurt claims, in passing, that while the ‘Frankfurt Counterexamples’2 are counterexamples to the Principle of Alternate Possibilities (PAP: An agent is morally blameworthy3 for what she has done only if she could have done otherwise), they are not counterexamples to the famous Kantian maxim that ‘Ought’ implies ‘Can’. In an Analysis...

Higher-Order Interpretations and Program Complexity

Polynomial interpretations and their generalizations like quasi-interpretations have been used in the setting of first-order functional languages to design criteria ensuring statically some complexity bounds on programs [8]. This fits in the area of implicit computational complexity, which aims at giving machine-free characterizations of complexity classes. In this paper, we extend this approac...