Mario Bunge

SEVEN DESIDERATA FOR RATIONALITY

Many of us take pride in being rational animals, but only philosophers have attempted to find out what rationality is (or what ‘rationality’ means). However, for better or for worse they have not reached a consensus. It is for the better, because lack of consensus may indicate that the problem is still open. And for the worse, because dissensus may indicate confusion, which is often a result of superficiality. I submit that a root of our problem is that the word ‘rationality’ stands for at least seven different concepts. I shall also argue that these concepts and the desiderata they entail, are ordered in a certain manner, and that singling out any of these desiderata, at the expense of the others, leads to partial rationality, an easy prey to irrationalism. Therefore I shall make a plea for global or scientific rationality. Finally, I will suggest that Popper and Chomsky, who pass for being the contemporary champions of , profess only a bounded rationalism. I shall also suggest that paraconsistent logic and decision theory, for all their mathematical apparatus, are pseudorationaI. All this will be done sketchily: the subject is large and complex enough to deserve a systematic and exact book- length study.

1. Seven Concepts of Rationality

I shall distinguish the following concepts of rationality: (i) conceptual: minimizing fuzziness (vagueness or imprecision); (ii) logical: striving for consistency (avoiding contradiction); (iii) methodological: questioning (doubting and criticizing) and justifying (demanding proof or , favourable or unfavourable);

In: E. Suárez-Iñiguez (ed.), The Power of Argumentation (Poznań Studies in the of the and the , vol. 93), pp. 117-128. Amsterdam/New York, NY: Rodopi, 2007.

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(iv) epistemological: caring for empirical support and avoiding conjectures incompatible with the bulk of the body of scientific and technological ; (v) ontological: adopting a consistent world view compatible with the bulk of the and technology of the day; (vi) valuational: striving for goals which, in addition to being attainable, are worth being attained; (vii) practical: adopting means likely to help attain the goals in view. Mathematicians and logicians excel at conceptual, logical, and meth- odological rationality. Scientists are supposed to abide by methodo- logical, epistemological, and ontological rationality. Technologists, managers, and men of action are likely to stress valuational and practical rationality. But most of us do not stick consistently to any of the seven rationalities, and few if any value all seven. Those who do will be called “full rationalists.” Philosophical rationalists have stressed the first three types of rationality. Value theorists, moral philosophers, and the occasional social scientist (in particular ) have focused on the last two (Wertrationalität and Zweckrationalität). On the other hand epistemological and ontological rationality, though often practiced, have been typically overlooked by rationalist philosophers. Moreover, what I have called “epistemological rationality” usually goes by the name of “the principle of .” I suggest that this is a misnomer, for it is one thing to look for empirical support, and another to postulate that experience is the only source of knowledge – which happens to be the first axiom of empiricism. One may care for experience while being a (global) rationalist, just as one may study behaviour without being a behaviourist. The difference between rationalists lato sensu and empiricists, with regard to experience, is that between “tap” and “top”: whereas the former demand that experience be always on tap, and reason always on top, empiricists wish to reverse these roles.

2. The Rationality System

The various concepts of rationality distinguished in the last Section are not mutually independent but form a system. In , they are ordered in the way they occur in the list included in that Section: they constitute a partially ordered set. We proceed to prove this claim.