The Logic of Decision

Prometto che non continuerò a pubblicare post con lunghe citazioni, ma queste due mi sono state suggerite da una chiacchierata con Hykel: riguardano i rapporti decisioni - logica. Già l'altro testo di Knight ne parlava. Se leggete la seconda, tenete presente che è del 1954 e mi sembra che dia tuttora da riflettere parecchio!

Kenneth J. Arrow, "Is Bounded Rationality Unboundedly Rational?", in Mie Augier and James G. March, eds., Models of a Man. Essays in Memory of Herbert A. Simon, MIT Press, 2004:

Rationality, whether substantive as in neoclassical economics or procedural along the lines stressed by Simon, is a process of logical inference (every computation is such a process). It proceeds from knowledge of a problem to knowledge of an answer to it (in the sense of a method of handling it). It raises questions such as what is meant by "knowing" something and in what sense can we infer or otherwise proceed from knowing some propositions to knowing others.

Leonard J. Savage, The Foundations of Statistics, 2nd revised edition, Dover Publications, 1972, pp. 6-7:

Reasoning is commonly associated with logic, but it is obvious, as many have pointed out, that the implications of what is ordinarily called logic are meager indeed when uncertainty is to be faced. It has therefore often been asked whether logic cannot be extended, by principles as acceptable as those of logic itself, to bear more fully on uncertainty. [...]

First, since logic is concerned with implications among propositions, many have thought it natural to extend logic by setting up criteria for the extent to which one proposition tends to imply, or provide evidence for, another. It seems to me obvious, however, that what is ultimately wanted is criteria for deciding among possible courses of action; and, therefore, generalization of the relation of implication seems at best a roundabout method of attack. It must be admitted that logic itself does lead to some criteria for decision, because what is implied by a proposition known to be true is in turn true and sometimes relevant to making a decision. Should some notion of partial implication be demonstrably even better articulated with decision than is implication itself, that would be excellent; but how is such a notion to be sought except by explicitly studying decision? [...]

Second, it is appealing to suppose that, if two individuals in the same situation, having the same tastes and supplied with the same information, act reasonably, they will act in the same way. Such agreement, belief in which amounts to a necessary (as opposed to a personalistic) view of probability, is certainly worth looking for. Personally, I believe that it does not correspond even roughly to reality, but, having at the moment no strong argument behind my pessimism on this point, I do not insist on it. But I do insist that, until the contrary be demonstrated, we must be prepared to find reasoning inadequate to bring about such complete agreement. In particular, the extensions of logic to be adduced in this book will not bring about complete agreement [...]