How does one think about things that are uncertain? Going outside without an umbrella, changing jobs, investing in stocks… We can entertain no firm beliefs about the future, but we think about it all the time, by ourselves and with others. Afflicted with doubt, we feel obliged to control it and make the best possible decisions. This ambition inspired the mathematics which is the topic of this book. Probability theory addresses simple problems – such as assessing the quality of a wager – in order to develop a language for thinking about uncertainty. The book is structured into six lively conversations (one for each face of a die) and explores six encounters between probability mathematics and everyday experience. Gamblers throw dice, potential criminals see charges against them dismissed, exit polls are performed during elections, someone parts with an egg in exchange for a chicken, promises are made in good faith, and travellers take to the sea. Lots of events come to pass, in other words, but the mathematics that attempts to describe those events remains the same.

Marco Li Calzi teaches Mathematical Methods for Economic Analysis at the Ca’ Foscari University in Venice.