explores the concept of rationality not as a matter of scientific or literal belief, but as a practical tool for survival and risk management. It argues that many apparent superstitions and biases are actually evolutionary shortcuts that aid in avoiding ruin, asserting that survival precedes truth and philosophy. The source uses examples such as the optical deceptions in Greek architecture and the function of religion and dietary laws to illustrate how beneficial "errors" or non-scientific beliefs can lead to enhanced outcomes and group longevity. Ultimately, the text defines true rationality as any action or belief that allows for continued existence, emphasizing the importance of revealed preferences and evolutionary considerations over intellectual explanations or "cheap talk."