Daniel Kahneman was a celebrated and influential scholar, trained in psychology but with a seemingly limitless way of thinking about the world. In 2002, he won a Nobel Prize in economics; in 2011, he published a popular book called Thinking, Fast and Slow. His primary topic was human decision-making, especially how we make decisions under uncertainty. His work has influenced people in government and policy-making, in medicine and finance, in the military and the criminal-justice system, and more.