Is libertarianism a progressive doctrine, or a reactionary one? Does libertarianism promise to liberate the poor and the marginalized from the yoke of state oppression, or does talk of "equal liberty" obscure the ways in which libertarian doctrines serve the interests of the rich and powerful? Through an examination of the history of libertarianism, The Individualists: Radicals, Reactionaries, and the Struggle for the Soul of Libertarianism (Princeton University Press, 2023) argues that the answer is (and always has been): both. In this book, the authors explore the neglected 19th century roots of libertarianism to show that it emerged first as a radical and progressive doctrine. Libertarianism took a conservative turn in the 20th century primarily as a reaction against the rise of state socialism. Now, with international communism no longer a threat, libertarianism is in the midst of an identity crisis, with progressive and reactionary elements struggling to claim the doctrine as their own, most notably on issues of race. This book tells the history of libertarianism through an examination of six defining themes: private property, skepticism of authority, free markets, individualism, spontaneous order, and individual liberty. Matt Zwolinski is professor of philosophy at the University of San Diego, where he is director of the Center for Ethics, Economics, and Public Policy. John Tomasi is president of Heterodox Academy in New York City.Caleb Zakarin is the Assistant Editor of the New Books Network.