Jon Elster

“What, finally, are the functions of reason and rationality in human behaviors? They are the functions, respectively, of the prince’s tutor and his councilor. The tutor teaches the prince to promote the public good in the long term. The councilor tells him how to act in order to achieve his goals, whatever they might be, in the most efficient way. It is not incumbent upon the councilor to impose the demands of reason; but if the tutor has done his job well, the prince will make them his own.”

“The theory of rational action may therefore fail, because it is unable to produce unique prescriptions and predictions. It may also fail if the agents’ behavior does not conform to predictions, whether these are unique or not; that is, if the agents are irrational. There are multiple sources of irrationality, hot or cold.”

“The premise of this statement is what one might call the principle of non-indirection. I call “indirection” an indirect operation that makes it possible to arrive at a certain result through two successive actions, the first of which serves only to make the second possible. ... This principle is not limited to rational actions. ... The principle of non-indirection thus expresses a broader idea of coherence that includes the emotional as well as the rational.”

“For a rational actor, the information he uses to shape his beliefs is a variable rather than a given. Before deciding how to act, he has to make a preliminary decision concerning the quantity of resources he is prepared to invest in looking for the relevant facts. A general must not attack before he has surveyed the terrain, or a surgeon operate before he has examined the patient. However, they must not delay too long, for then they may be surprised by the enemy’s attack or flight, or by the patient’s death.”

“Biases are either “hot” (that is, produced by the agent’s motivational system) or “cold” (more similar to optical illusions).”

“For action to be rational, the beliefs on which it is based must themselves be well founded. In turn, this requirement is divided into two parts. On the one hand, the beliefs must be unbiased with respect to the information the agent possesses; on the other hand, he must gather an optimal amount of information.”

“In a general way, we can represent the present value of a future good as a function of the time separating the present from this future. In the classical conception, an exponential future discount is stipulated, which implies that the curves corresponding to two distinct future goods, one small and immediate, the other large and more remote, never intersect. According to more recent research, however, it seems that this discount typically takes a hyperbolic form.”

“In this reconstruction, the idea of reason comprises three elements: impartiality with regard to persons, temporal impartiality, and rational or well-founded beliefs. No doubt we should add goodwill, in order to exclude impartial malice.”

“Characterized in this way, interest properly understood is an amalgam of objective and subjective elements. An entirely objective conception would substitute true beliefs for well-founded beliefs. But it is impossible to make political decisions dependent on the possession of truth.”

“Let us take first an absurd example: always preferring goods that come on Thursdays to those that come on Wednesdays, solely because of a preference for that particular day of the week. As we shall see, this is not contrary to the principles of rational choice, but it is certainly contrary to reason. The simple preference for Thursdays is a reason, but reason also demands the reason for that reason. And obviously there is none.”