This book re-examines the philosophical roots of classical liberal political economy, as well as addressing the relationship between the empire and liberalism. It proposes an interpretive model based upon the interconnection between distinct theories of natural rights and the harmony of interests. It takes a fresh look at classical liberalism by exploring economic arguments in thinkers like Thomas Hobbes, Thomas Paine, John Trenchard and Thomas Gordon, who are not typically viewed as economic thinkers, and by highlighting the importance of Bernard Mandeville and Adam Smith in the development of interest-based liberalism. It also re-examines lesser-known economic tracts by thinkers such as John Locke, David Hume and John Stuart Mill in light of their more well-known political writings. With classical liberal assumptions still prominent in contemporary debates about economic justice, it is vital for every democratic citizen to understand the complex origins and development of the ideas that did so much to shape our world today.