The masters of the philosophy of 18th century: Newton and Locke

Between the great theological systems of Malebranche, Leibniz, Spinoza, and the massive philosophical architectures of Schelling, Hegel and Comte, the eighteenth century seems to be a moment of relaxation for the synthetic and constructive spirit.

It has been variously appreciated: it has attracted the disdain of historians of philosophy who, apart from the doctrines of Berkeley, Hume and Kant, find in it only summary, disjointed, unoriginal thoughts, made for the pamphlet, and betraying party spirit; on the other hand, the violent reaction which marked the beginning of the 19th century contributed to making it appear as a negative, destructive, critical century; we make as many different judgments about him as about the French Revolution, which we consider to be its true fruit.

What marks the beginning of the 18th century is the rapid decline, then the profound fall of the great systems which, under Cartesian inspiration, had endeavored to unite the philosophy of nature and the philosophy of mind. The masters of the 18th century are Newton and Locke: Newton in whom the substantial part of his thought, natural or physical philosophy, has only a very loose link with his doctrines on spiritual realities in which he is rather inclined to believe by personal mysticism, than making them the object of methodical meditations which would be inseparable from its physics; Locke, the author of a philosophy of mind, which remains without essential connection with the contemporary development of mathematical and physical sciences in Boyle or Newton; because, if Locke and especially some of his successors seek, as we will see, to establish a certain affinity between the mind and the material world as represented by the theory of attraction, we must see there something completely different from methodical unity, which Descartes had claimed to establish between the various parts of philosophy: in truth, a simple metaphor which imagines the mind on the model of nature revealed by Newton, with the illusion of obtaining, in the sciences of the mind, as marvelous an achievement as in the natural sciences.

However paradoxical the thing may seem, this radical separation between nature and spirit dominates the thought of the 18th century; the dualist government of Locke and Newton continues to govern intelligences to the end, barring the protests that we will have to register.