Rationality: What It Is, Why It Seems Scarce, Why It Matters

Rationality: What It Is, Why It Seems Scarce, Why It Matters is a 2021 book written by Canadian-American cognitive scientist Steven Pinker. The book was published on September 28, 2021, by the Viking imprint of Penguin Random House.

It argues that rationality is a key driver of moral and social progress, and it attempts to resolve the apparent conflict between scientific progress and increasing levels of disinformation. Pinker explains several concepts underlying rationality, including from the fields of logic, probability theory, statistics, and social choice.