In the seventeenth century British natural philosophers explored the cognitive value of mechanical trades. From the beginning, these explorations of down-to-earth manual processes were expressed in oblique and ironic texts. In utopian fictions by Thomas More, Francis Bacon and Gabriel Plattes, mechanical trades were presented as at once near-at-hand and alien to the world of books and codified knowledge. Bacon’s mid-century followers tried to negotiate these difficulties in plans to compile a comprehensive ‘History of Trades’. In the period’s most widely circulated didactic text, Izaac Walton’s Compleat Angler, the tacit and haptic dimension of a humble pass-time was explored through genial satire and eccentric textual design. Later, one highly literate artisan, the printer and instrument maker Joseph Moxon, gave thought to the difference between the artisanal expertise he employed as a manual technician and the theoretical knowledge he dealt with as a writer and fellow of the Royal Society.

Chapter 4 connects the emergence of transformative demographic governance to changes in natural philosophy, in particular to Francis Bacon’s works and their influence among projectors associated with the Hartlib Circle in the mid-seventeenth century. The problem of managing the qualities of populations in an empire raised the question of natural constraints on the power of policy to “improve” populations; the chapter examines Hartlibian projects concerned with this question on a large scale, including some in which putatively immutable racial boundaries and the enslavement of Africans indicate both limits to and paradoxes of demographic governance. It then turns to Cromwellian Ireland, showing that opposed arguments for either Irish transplantation or English –Irish mixture proceeded from a similar centering of demographic governance. Mid-century projects fed into William Petty’s “political arithmetic” in the Restoration. This fused Baconianism, alchemical ideas and quantification, treating the control of the numbers and of the economic, political, religious and cultural qualities of populations in England, Ireland and the empire as essentially similar problems for the state.