De Finetti's probabilism

Abstract

If de Finetti got it from Hume, then Hume got it from Carneades (ca. 200 B.C.), via Cicero, Sextus Empiricus, Montaigne, and Bayle.2 It is something of a pun to call it “probabilism” over the whole 2000 years and more of that line, but you can see why it is so called by dipping into an English translation of Cicero’s Latin rendering (in a dialogue) of the Greek of Carneades’s student, Clitomachus:3 Carneades holds ... that there is no presentation of such a sort as to result in knowledge through perception, but many that result in a judgement of probability. For it is contrary to nature for nothing to be probable, and entails that entire subversion of life of which you, Lucullus, were speaking; accordingly even many sense-percepts must be deemed probable, if only it be held in mind that no sense-presentation has such a character as a false presentation could not also have without differing from it at all.