In this spirited manifesto, Gopnik paints a sweeping portrait of modern liberalism’s founding principles and accomplishments and makes the case for the theory’s continued relevance in today’s struggle to build decent and inclusive societies. Gopnik traces liberalism’s origins to the Enlightenment and the early modern humanistic tradition. It was rooted in a belief—articulated by thinkers such as David Hume and Adam Smith—in the inherent sociability of people and the human capacity for mutual respect. Liberal society is grounded not in blood and soil, nor in traditional authority, but rather in an idea of “shared choice,” a vision of a political community held together by crosscutting values: liberty, equality, and toleration. For Gopnik, liberalism is best understood not as a formal doctrine, a set of abstract principles, or a group of fixed political institutions, but as a way of life. Across the centuries, liberal thought has been united by “the liberal temperament,” an embrace of pluralism and reform and a skepticism of utopias. Liberalism’s great project, as Gopnik eloquently argues, is the unending struggle to build a society with both liberty and equality at its core.