Book excerpt: Roots of Freedom is a primer on the thinkers and ideas that, over many centuries, have laid the foundations of free societies. Concepts such as the rule of law, independent judiciary, limited government, free markets, and individual autonomy are traced in the writings of (among others) Luther, Machiavelli, Hobbes, Locke, Montesquieu, Hume, Adam Smith, the American founders, Alexis de Tocqueville, and John Stuart Mill.