… is from page 64 of Joel Mokyr’s 2009 book, The Enlightened Economy: An Economic History of Britain 1700-1850:
By the start of the eighteenth century, the British state was still wedded to mercantilist principles, which were in many ways a justification for rent-seeking (Ekelund and Tollison, 1981). Enlightenment thought challenged the basic assumption of the mercantilist world, namely that the economic game, and above all the commerce between nations, was zero-sum such that the gains of any agent or any economy inevitably came at the expense of another.