The spread of capitalism and democracy has inspired controversies over the direction of the modern world. Some scholars see a future of "multiple modernities," in which Western liberal democracy will give way to divergent political and economic systems; others see universal forces pushing all societies toward liberalism. In this spirited manifesto, Ferris, a science journalist, argues that science and the rise of "science societies" are the fundamental drivers of liberty and democracy. Societies need science to advance, and science requires political openness. This, of course, is an old thesis, rooted in the Enlightenment conviction that knowledge, innovation, freedom, and social advancement go together. In this restatement, Ferris traces the dual scientific and democratic revolutions from their Renaissance, Enlightenment, and early modern origins to the titanic twentieth-century battles between the liberal democracies and their fascist and communist rivals. Ferris also explores the scientific orientation of the United States' founders, such as Thomas Jefferson and Benjamin Franklin, and its relevance to their constitutional thinking and their noble "experiment" of a new nation. The Science of Liberty is sweeping and provocative, even if many may still doubt that science can extinguish prejudices, parochialisms, and illiberal impulses.