This chapter marks the introduction of Part 4 of the book. Part 4 is primarily centered on choices and how they relate to cognitive intuition. Kahneman goes on to share his encounter with psychologist and economists whom he owes his several approaches to System 1. Accordingly, psychologists focus on System 1 when evaluating people’s minds while economists consider System 2. Kahneman expounds the theory of Bernoulli Fechner and draws to the reader’s attention to some critical errors in Bernoulli’s reasoning. Kahneman also sheds light on the Expected Utility, which is Fechner’s major milestone in his study of expectations.