This book aims to re-evaluate the relations between two major ideologies that have been increasingly contested in recent years, yet continue to be invoked or rejected as foundational systems for political thought or action. With socialism conceiving of itself as an alternative to economic liberalism, the two systems of thought emerged partially in opposition to each other. However, this book seeks to redefine their specificities and the way in which they have not only opposed each other but drew on common notions or paradigms to become both competing and complementary systems of thought and practices. With contributions from eminent political scientists and historians of political and economic thought, the book examines how the polarisation of debates and politicisation of concepts such as property, freedom, the individual, or the State, serve to construct the adversary and form a basis for political commitment. Offering an interdisciplinary assessment of the relation between liberalism and socialism, the authors help to make sense of current debate on individual freedom, political obligation and the changing role of the State. Providing an innovative perspective, this edited collection will be of interest to scholars and students researching political and economic thought, history or science, as well as anyone seeking to understand current developments affecting Western societies, and their past, present, and future ideologies.