Thinker · TH-0088
Bruno de Finetti
Bruno de Finetti was an Italian probabilist and statistician, born in Innsbruck, who worked as an actuary in Trieste and later taught in Trieste…
1906 – 1985 · Innsbruck; Trieste; Rome
Traditions: Analytic
Bruno de Finetti was an Italian probabilist and statistician, born in Innsbruck, who worked as an actuary in Trieste and later taught in Trieste and Rome. He developed the subjectivist interpretation of probability, on which probabilities are coherent degrees of belief rather than features of the world. His Dutch book argument shows that degrees of belief violating the probability axioms expose an agent to a set of bets guaranteed to lose.
Key ideas
- Probability is a degree of belief held by an agent, not an objective property of events.
- Coherence requires that no set of bets an agent accepts can guarantee a loss; this forces conformity with the probability axioms.
- Exchangeability explains how subjective beliefs come to behave as if there were objective chances.
- Learning from evidence is the updating of coherent beliefs.
Major works
- "Sul significato soggettivo della probabilità" (1931)
- "La prévision: ses lois logiques, ses sources subjectives" (1937)
- Teoria delle probabilità (1970; Theory of Probability, 1974–75)
In the conversation
- Question My son says my rain forecasts could be “Dutch-booked”. What does that mean?
- Debate Not every coherent prior is rational: subjective Bayesianism is far too permissive
- Question QBism says the wavefunction is my degrees of belief. What exactly is it claiming?
- Reading group Reading group: Frank Ramsey, “Truth and Probability” (written 1926)
In the Journal
In the Coordinates
The questions of philosophy where Bruno de Finetti takes a place, from The Coordinates of Thought.
- 2.8 Formal Epistemology By how much should this evidence move you?