The Extended Theory of Instrumental Rationality and Means-Ends Coherence

In Rational Powers in Action, Sergio Tenenbaum sets out a new theory of instrumental rationality that departs from standard discussions of means-ends coherence in the literature on structural rationality in at least two interesting ways: it takes intentional action (as opposed to intention) to be what puts in place the relevant instrumental requirements, and it applies to both necessary and non-necessary means. I consider these two developments in more detail. On the first, I argue that Tenenbaum’s theory is too narrow since there could be instrumental irrationality with respect to an intention to X even if one is not yet engaged in any relevant intentional action. On the second, I argue against Tenenbaum’s claim that “an agent is instrumentally irrational if she knowingly fails to pursue some sufficient means to an end she is pursuing.