Freedom is among the most important values in political life, yet there has always been a great deal of disagreement about what this value demands from us. Libertarians argue that it requires that we protect each person's right to own and exchange private property. Liberals argue that it requires that we protect a wide range of civil and political liberties, including rights such as the freedom of expression and freedom of conscience, as well as the rights of private property. Socialists argue that it requires that we eliminate hierarchical systems of authority and replace them with more collaborative forms of decision-making. The goal of my dissertation is to enter into these disagreements and defend a comprehensive approach to the value of freedom. My central claim is that the various demands of freedom are best understood as aspects of a deeper concern for autonomy. According to what I call the social democratic conception of freedom , our basic institutions respect the value of freedom insofar as they respect the value of our personal and political autonomy. I develop a view of personal autonomy by engaging critically with Harry Frankfurt's second-order desire theory of the will, and I develop a view of political autonomy by extending this view of personal autonomy to the political domain. I argue that the resulting conception of freedom improves on the most important contemporary conceptions, including those advocated by Robert Nozick, John Rawls, Philip Pettit and Amartya Sen. It does so by providing us with a better account of the relationship between freedom and democracy, on the one hand, and a better account of the relationship between freedom and education on the other. The most significant implication of the social democratic conception is that freedom does not require that we liberalize markets, as libertarians contend, but that we deepen the role that democracy plays in the economy---and in social life more generally. The argument throughout is strongly influenced by John Rawls and G.W.F. Hegel and represents a novel attempt to develop common themes in their work.