Counterexamples to ought implies can
Does the claim that a certain person ought to do something entail that they have the ability to do this thing? Here are some challenges to the view that there is this entailment (see also Buckwalter 2019).
Sometimes it is reasonable complain about being in a situation in which we ought to do something but are unable to. Michael Stocker gives the example of a man who believes he should pick up some broken glass on a path used by children who walk barefoot. But “If some of the children lasso him and tie him to a tree, he can certainly complain that they are making it impossible for him to do what he ought to do (or ought to be doing).” (1971: 312)
Julia Driver presents the following three inconsistent propositions
(1) Whenever a person makes a promise to do X, he thereby puts himself under an obligation to do X.
(2) If someone is obligated to do X, then he can do X.
(3) Sometimes people make promises they cannot keep.
One solution to the inconsistency is to get rid of (2).
Alexandra King presents this counterexample. Suppose you ought to apologize at a certain time. But apologizing involves more than just saying sorry. It involves expressing certain emotions in saying this and therefore having these emotions. But emotions are not something that are under immediate control, such that one can have the emotion at a given time just by willing to have it. Thus it may be that a person ought to apologize at a given time, or at some point within a given period of time, but cannot apologize at that time, because they do not have the appropriate emotions. King gives the example of parents rightly telling their child to apologize to Grandma.
Buckwalter, W. 2019. Theoretical Motivation for “Ought Implies Can.” Forthcoming in Philosophia.
Driver, J. 1983. Promises, obligations and abilities. Philosophical Studies 44: 221-223.
King, A. 2014. Actions That We Ought, But Can’t. Ratio 27: 316-327.
Stocker, M. 1971. ‘Ought’ and ‘Can’. Australasian Journal of Philosophy 49: 303-316.