John Brunero

Some philosophers have tried to establish a connection between the normativity of instrumental rationality and the paradox presented by Lewis Carroll in his 1895 paper “What the Tortoise Said to Achilles.” I here examine and argue against accounts of this connection presented by Peter Railton and James Dreier before presenting my own account and discussing its implications for instrumentalism (the view that all there is to practical rationality is instrumental rationality). In my view, the potential for a Carroll-style regress just shows us that since instrumental rationality involves a higher-order commitment to combine our willing an end with our taking the necessary means, it therefore cannot, on pain of regress, itself be added as a conjunct to one of the elements to be combined. This view does not support instrumentalism.

It is commonly thought that one is irrationally akratic when one believes one ought to F but does not intend to F. However, some philosophers, following Robert Audi, have argued that it is sometimes rational to have this combination of attitudes. I here consider the question of whether rational akrasia is possible. I argue that those arguments for the possibility of rational akrasia advanced by Audi and others do not succeed. Specifically, I argue that cases in which an akratic agent acts as he has most reason to act, and cases in which an akratic agent achieves a kind of global coherence he wouldn’t have achieved had he instead formed intentions in line with his best judgment, do not establish the possibility of rational akrasia. However, I do think that rational akrasia is possible, and I present two arguments for this thesis. The first argument involves a case in which one is incapable of revising one’s belief about what one ought to do, where one also acknowledges this belief to be insufficiently supported by the evidence. The second argument involves a case in which one rationally believes that one ought to have an akratic combination of attitudes.