01/18/2005: Philosophical Ideas II: Attributions of Ability
From David Lewis's essay "The Paradoxes of Time Travel":
To say that something can happen means that its happening is composssible with certain facts. Which facts? That is determined, but sometimes not determined well enough, by context. An ape can't speak a human language -- say, Finnish -- but I can. Facts about the anatomy and operation of the ape's larynx and nervous system are not compossible with his speaking Finnish. The corresponding facts about my larynx and nervous system are compossible with my speaking Finnish. But don't take me along to Helsinki as your interpreter: I can't speak Finnish. My speaking Finnish is compossible with the facts considered so far, but not with further facts about my lack of training. What I can do, relative to one set of facts, I cannot do, relative to another, more inclusive, set. Whenever the context leaves it open which facts are to count as relevant, it is possible to equivocate about whether I can speak Finnish. It is likewise possible for me to equivocate about whether it is possible for me to speak Finnish, or whether I am able to, or whether I have the ability or capacity or power or potentiality to. Our many words for much the same thing are little help since they do not seem to correspond to different fixed delineations of the relevant facts.
For further reflection: certain ethical claims seem to be logically related to corresponding attributions of ability, i.e. "ought implies can." If attributions of ability are context dependent as Lewis claims, what does this tell us about the corresponding ethical claims?
(Lewis's essay can be found in The Philosophy of Time.)
Brock on 01.18.05 @ 09:24 PM CST