Structural Rationality and Coherentism

Abstract

Structural irrationality of individual behaviour patterns can only be rectified by a specific form of self-control. This can be illustrated using an ordinary, simply-structured example: a long-standing smoker asks himself whether he ought to give up smoking. The smoker’s subjective valuations are such that the time integral of his value function increases monotonously the sooner he gives up smoking. The valuation does not only include the smoker’s expected general state of health (a probabilistic estimation), but also the pleasure he undoubtedly enjoys in smoking a cigarette, possibly it also includes the damage the smoke of his cigarettes does to other people, etc. If he still does not give up smoking, his case seems to be a clear instance of ‘akrasia’ or weakness of the will: weighing up all different evaluative aspects, he knows what would be the best thing to do, but he still cannot get himself to do it. This interpretation, however, is not conclusive. It might just as well be the case that the smoker acts consequentially rational, if he does not give up smoking — despite the fact that the time integral over his valuation function increases monotonously the sooner he gives it up. The reason for this is that he — as a consequentialist person — is (under normal circumstances) never confronted with the decision to give up smoking.