What is Natural Right and History about?

Natural Right and History is Leo Strauss's sustained argument that the modern rejection of natural right — the idea that there is a standard of justice discoverable by reason, independent of convention and history — represents a profound intellectual and political crisis. Delivered as the Walgreen Lectures at the University of Chicago in 1949 and published in 1953, the book is simultaneously a critique of modern political philosophy, a recovery of ancient Greek thought, and a warning about the political consequences of relativism.

Strauss begins by distinguishing natural right from natural law in the theological sense. His concern is with the philosophical question: is there any standard of justice that is not merely the product of a given culture, historical period, or act of political will? He identifies two modern doctrines that deny this possibility. The first is historicism — the view that all thought is conditioned by its historical situation, so that no claim to universal validity can be made. The second is what he calls the "value positivism" of Max Weber: the view that science can describe facts but cannot adjudicate between ultimate values, which are a matter of choice rather than reason.

Strauss argues that both of these doctrines are not merely false but politically dangerous. If there is no standard of justice beyond what a society happens to affirm, then there is no basis on which to criticize injustice — including the injustices of totalitarian regimes. The nihilism implicit in modern social science, Strauss argues, leaves liberal democracy without a principled defense of itself. To find that defense, Strauss turns to the ancients: Socrates, Plato, and Aristotle, and then to the classical natural right theory in Locke, which he reads as both indebted to and a departure from the classical tradition.

Natural Right and History is a difficult book. Strauss writes with precision and density, assumes significant philosophical background, and is often engaged in arguments that require knowing the positions he is criticizing. It is also a controversial book. Strauss's readings of Plato and Locke are disputed by classicists and historians of philosophy, and his overall argument has been challenged from multiple directions — as nostalgic, as politically reactionary, as obscurantist. But its core question — whether there is any rational basis for judging one set of values better than another — is genuinely urgent, and Strauss poses it with more rigor and historical depth than almost anyone else.