Italian mathematician and philosopher. Born in Innsbruck, and educated at Milan, de Finetti worked on many different branches of mathematics, in Milan, in Rome, and from 1931 in the Assicurazioni Generali di Trieste, as an actuary and administrator. In 1961 he assumed the chair of mathematics of probability in Rome. He published over three hundred mathematical and scientific articles. Philosophically he is remembered alongside Ramsey as the pioneer of the subjective view of probability, since developed into the school of statistical thought known as personalism. De Finetti's first work dealing with the topic was Probabilismo: saggio critico sulla teoria della probabilità e sul valore della scienza (1931). He is best known in the English-speaking world for La Prévision: ses lois logiques, ses sources subjectives (1937, trs. as Foresight: its Logical Laws, its Subjective Sources, 1967), and the two-volume Teoria della probabilità (1970, trs. as Theory of Probability, 1974). De Finetti was an uncompromising error theorist: he places probability in the same category as the aether or fate, and prefaces the latter work with the remark ‘my thesis is simply this: probability does not exist’. Surprisingly, he ends his Probabilismo text by connecting the freedom given by rejecting this superstition with the exhilarating liberations of fascism. See also representation theorem.