This thesis studies the relationship between the particular interests of individuals and the common good, as it is conceived by various moral and political philosophers in earlymodern England (c.1640-c.1740). Interests are spoken of in English translations of Italian and French texts in the early seventeenth century, and are often used to describe goods or desires that are morally ambiguous. The vocabulary becomes commonly used in political tracts during the English Civil Wars, and this is where the thesis begins. We then move on to an analysis of the place of interests in Hobbes’s changing civil science. Hobbes continues to see interests as being morally ambiguous and dangerous to the common good. The third chapter deals with the republican tradition (epitomized by James Harrington), in which thinkers begin to conceive how interests might be manipulated to serve the common good. Chapter 4 deals with the men of latitude of the Restoration, who first conceive that interests are in fact identical with our moral virtues. We thereby come to see that the important questions regarding interests in the restoration revolved around religion and morality, rather than (as is commonly assumed) around trade. The fifth chapter deals with the commonwealth theorists, who became increasingly concerned that Charles II’s court, and subsequently the court whigs, were beginning to constitute an interest separate from that of the people. We then come to a discussion of Bernard Mandeville, who is generally thought to be a critic of the commonwealthmen, but (in his use of the vocabulary of interests) actually bears quite a close intellectual resemblance to them. The thesis ends with an account of a number of reactions to Mandeville, chief among them, Joseph Butler, who argues that not only are our interests identical with virtue, but they also naturally serve the common good.