Instrumental Rationality

Abstract

Abstract Rationality requires that we intend the means we believe are necessary for achieving our ends. This book explores several interrelated issues regarding the formulation and status of this requirement of means–ends coherence. I argue that means–ends coherence is a genuine requirement of rationality, and cannot be explained away as a myth, confused with a disjunction of requirements to have, or not have, specific attitudes. But nor, I argue, is means–ends coherence strongly normative in that we always ought to be means–ends coherent. Why is this requirement in place? One popular strategy looks to the connection between intention and belief, and aims to explain means–ends coherence by appealing to the requirements of theoretical rationality. I argue that this strategy is unpromising. I instead propose that we look to the constitutive aim of intention. Just as belief has a constitutive aim (truth) that can explain some of the theoretical requirements of consistency and coherence governing beliefs, intention has a constitutive aim (what I call “controlled action”) that can explain some of the requirements of consistency and coherence governing intentions. In particular, I argue that we can understand means–ends coherence by understanding the constitutive aims of both of the attitudes governed by the requirement, intention and belief. In being means–ends incoherent, you are setting yourself up to fail, assuring that you either have a false instrumental belief or your intention won’t issue in action.