In politics as in philosophy, Voltaire was no system-builder. He had a deep suspicion of ‘systems’, and his political writings do not combine readily to reflect a systematically argued world-view. ‘I write to act’, he once informed Jean-Jacques Rousseau (Best. D13221), and as a political thinker he tended to respond to events rather than metaphysical abstractions. He was remarkably well-informed, however, and his reading was wide. He knew the work of Grotius, Pufendorf, Hume, Bolingbroke, Montesquieu, Machiavelli, d'Argenson, Mably, Saint-Pierre, Quesnay, Le Mercier, Melon, Hobbes, Mandeville, Buffon, Beccaria, Rousseau and Locke although, astonishingly, evidence suggests he knew little of the latter's Two treatises on government (see Perkins 1965, Appendix 2, Crocker 1983, Thielemann 1959, Kotta 1966).

He drew constantly on this rich hinterland, but his allusions are deceptively casual, and often expressed in an ironic, tangential way. As he puts it in ABC, ‘we take what we like from Aristotle to Locke, and don't give a damn for the rest’. Only with Montesquieu, and to a lesser extent Rousseau, does he offer anything like a prolonged commentary on another theorist, even when we are led to expect one, as in the case of Beccaria. Voltaire's technique is to entertain, to provoke and to inform by means of satirical anecdote, outrageous vulgarisation and lively dialogue. Among his many gifts as a persuasive polemicist is his unrivalled ability to breathe life and a sense of human reality into the driest issue.