Identities—national, ethnic, cultural—are never simple. They dwell, uneasily, between the competing narrative lines of purity and impurity, homogeneity and heterogeneity, continuity and discontinuity. Over the past thirty years or so, this truth has been brought home to us by a global capitalism that has expanded the mobility of persons and things and deepened the relationships between them. The objects that today we are willing to host in our bodies; the electronic mediation of intimacy, sociability, and political action; the restless circulation of commodities and capital around the globe; the splicing of corporations across multiple nations; and the increasing...

For centuries, mixture was a basic concept in science. From Aristotle’s and Galen’s influential writings to the Islamic reception of Greek learning by Avicenna and Averroes, through Duns Scotus, Thomas Aquinas, and Renaissance thinkers such as Julius Scaliger and Giacomo Zabarella, mixture was indispensable if you wanted to explain what a body was and how it behaved.¹ Minerals, plants, animals, and humans were all characterized by different mixtures of four basic elements. These bodies could be understood only if you had a theory of mixture—of its variations, its locations, its balances and imbalances. But despite this broad acceptance of...

Renaissance ideas about natural magic, misinterpretations and critiques of Aristotle, the Calvinist taste for purity, the argument that nature was decaying, the revival of atomism—all of these factors populate the intellectual field that brought a number of seventeenth-century scientists to recognize mixture as a legitimate cause and fundamental reality. Whether that reality appeared as loose contexture, irreducible union, or heterogeneous assemblage made no ontological, theological, or moral difference. This view was radical. It threw out the idea that a proper body depended on the subordination of parts to whole, many to one, and matter to form. Atomists such as...

My argument has shown that the attempt in seventeenth-century England to imagine and justify political bodies that share sovereignty between multiple parts was assisted by changing scientific definitions of natural bodies. Adopting a mediated relationship between first and second causes, a diverse group of natural and political philosophers in the first half of the century sought to legitimize mixture and multitude and normalize heterogeneity, deformity, and mutation. Their vision of natural and political bodies offered a fundamental challenge to the norms of political order promoted by royalists and absolutists. To be unified, powerful, and civil, the anti-absolutists argued, political bodies...

I set out to understand the intellectual resources that allowed early eighteenth-century Englishmen to become assertive about mixture as the source of English perfections. I have written a semantic history that has tracked the revaluation of mixture and its conceptual horizon in seventeenth-century culture. The pursuit of this horizon has taken us through a diverse terrain. We have crossed several fields of inquiry, from geography, embryology, and chemistry to political science and philosophy. We have climbed some metaphysical heights and were rewarded with the sight of unexpected political bridges between Calvinists, Arminians, and Catholics. We saw that the paths of...