In Search of the Newton of the Moral World: The Intelligibility of Society and the Naturalist Model of Law from the End of the Seventeenth Century to the Middle of the Eighteenth Century

Montesquieu appears to have moved away from the normative field of natural law to turn instead to a positive description of facts and to search for their empirical regularity, thus making him the founder of sociology. As soon as L'Esprit des lois was published in 1748, the naturalist Charles Bonnet praised its author in the following terms: 'Newton discovered the laws of the material world, you, Sir, have discovered the laws of the intellectual world'. Montesquieu rejected the model based on the uniformity of laws and government, which had attracted Abbe de Saint-Pierre and Nicholas Malebranche. There is no doubt that the expression 'the Newton of the moral world' is pertinent. It reflects the prestige of natural philosophy in the seventeenth century and the importance of the analogy between the physical and moral worlds. But it also encourages a positivist interpretation, which concludes rather hastily on the predominance of the epistemological model of natural law from the eighteenth century onwards.