Steven Pinker's "Rationality" explores the nature of rational thought and why it often seems absent in human behavior. The author examines various tools of rationality, such as signal detection theory and Bayesian reasoning, highlighting cognitive biases and fallacies that impede sound judgment. Game theory is introduced to analyze strategic decision-making in situations involving multiple actors. The text further investigates the challenges of distinguishing correlation from causation and the importance of experimental design. Finally, it addresses the apparent crisis of irrationality in contemporary society, considering motivated reasoning, conspiracy theories, and potential remedies for improving our collective capacity for reason and truth-seeking.