Pat Rogers reviews what sounds like a fascinating new study, Wolfram Schmidgen’s Exquisite Mixture: The Virtues of Impurity in Early Modern England . In Schmidgen’s view “mixture is at the heart of everything, a constitutive part of meaning in all cultural activity. Far from polluting, impurity creates a healthier state of being,” and Schmidgen argues that the scientists and political thinkers of the seventeenth century agreed with him, who struggled “to displace ideas of order that privileged strong boundaries, clear forms and sovereign essences.”

His account of the scientific revolution shows “how writers such as Kenelm Digby repudiated Aristotelian physics and genetics, as well as Galen’s physiology. This line of discussion replaced traditional notions of balance and internal coherence among elements with a dynamic mishmash: the greater the heterogeneity of things, the more developed their state.”

The central figure is Robert Boyle, whose atomistic philosophy showed “that small admixtures could transform entities to produce artificial compounds more potent than any found in nature. This had obvious implications for the role of the scientist, who was now ‘enabled by his skill not barely to understand several Wonders of Nature, but also . . . to multiply and improve them.’

Political theorists followed suit: They “were ranged against the view of Hobbes that the multitude constituted nothing more than a ‘heap’ of particulars lacking in unity and legal standing, as they were against the belief of Browne that the muddled history of the English tongue led to corruption and debilitation in the language.” In the process, “mixed government came to be valued above absolutism. as the power structure seemed to require “porous borders” between the authorities and the people.”

At this point, nationalism was not necessarily a doctrine of purity, but could be the opposite: “Defoe’s True-Born Englishman , which conveniently appeared in January 1701, at the very outset of the new era. In some famous lines, Defoe anatomizes the racial composition of Britain as the product of a series of unplanned invasions, wars, waves of immigration and economic assimilation – a ‘compounded Breed’ drawn from the ‘mixt Relicks’ of its history.”

Rogers notes that Smidgen’s epilogue laments the Enlightenment purism. One hopes for a follow-up study that will push the story into the next century. It seems that even at this late date we have not quite outgrown the Pharisaical impulse.