Much of modern economic and financial theory is based on the assumption that people are rational, and thus that they systematically maximize their own happiness, or as economists call it, their “utility.” When Samuelson took on the subject in his 1947 book, he did not look into the brain, but relied instead on “revealed preference.”
现代经济学和金融学理论大体上基于人类理性的假设——人类总是系统性地最大化自身的快乐程度，即经济学家所谓的“效用”。萨缪尔森在1947年提出这一主题时，他并没有将研究目光投向大脑，而是提出了“显示偏好”。人的目标只能通过观察其经济行为而被显示。在萨缪尔森的指引下，一代又一代经济学家将自己的研究建立在理性假设的基础上，而不是决定思考和行为的生理结构上。