This book illustrates the deep roots of natural law doctrines in America's political culture. Originally published in 1931, the volume shows that American interpretations of natural law go to the philosophical heart of the American regime. The Declaration of Independence is the preeminent example of natural law in American political thought it is the self-evident truth of American society. Benjamin Wright proposes that the decline of natural law as a guiding factor in American political behaviour is inevitable as America's democracy matures and broadens. What Wright also chronicled, inadvertently, was how the progressive critique of natural law has opened a rift between and among some of the ruling elites and large numbers of Americans who continue to accept it. Progressive elites who reject natural law do not share the same political culture as many of their fellow citizens. Wright's work is important because, as Leo Strauss and others have observed, the decline of natural law is a development that has not had a happy ending in other societies in the twentieth century. There is no reason to believe it will be different in the United States.