So the curtain fell upon this strange tragi-comedy of a man of letters. There is no better epilogue than words of his own:—“We fix our gaze on the ruins of a triumphal arch, of a portico, a pyramid, a temple, a palace, and we return upon ourselves. All is annihilated, perishes, passes away. It is only the world that remains; only time that endures. I walk between two eternities. To whatever side I turn my eyes, the objects that surround me tell of an end, and teach me resignation to my own end. What is my ephemeral existence in comparison with that of the crumbling rock and the decaying forest? I see the marble of the tomb falling to dust, and yet I cannot bear to die! Am I to grudge a feeble tissue of fibres and flesh to a general law, that executes itself inexorably even on very bronze!”
CHAPTER IX.
CONCLUSION.
A few more pages must be given to one or two of Diderot’s writings which have not hitherto been mentioned. An exhaustive survey of his works is out of the question, nor would any one be repaid for the labour of criticism. A mere list of the topics that he handled would fill a long chapter. A redaction of a long treatise on harmony, a vast sheaf of notes on the elements of physiology, a collection of miscellanea on the drama, a still more copious collection of miscellanea on a hundred points in literature and art, a fragment on the exercise of young Russians, an elaborate plan of studies for a proposed Russian University,—no less panurgic and less encyclopædic a critic than Diderot himself could undertake to sweep with ever so light a wing over this vast area. Everybody can find something to say about the collection of tales, in which Diderot thought that he was satirising the manners of his time, after the fashion of Rabelais, Montaigne, La Mothe-le-Vayer, and Swift. But not everybody is competent to deal, for instance, with the five memoirs on different subjects in mathematics (1748), with which Diderot hoped to efface the scandal of his previous performance.
I.
Decidedly the most important of the pieces of which we have not yet spoken must be counted the Thoughts on the Interpretation of Nature (1754). His study of Bacon and the composition of the introductory prospectus of the Encyclopædia had naturally filled Diderot’s mind with ideas about the universe as a whole. The great problem of man’s knowledge of this universe,—the limits, the instruments, the meaning of such knowledge, came before him with a force that he could not evade. Maupertuis had in 1751, under the assumed name of Baumann, an imaginary doctor of Erlangen, published a dissertation on the Universal System of Nature, in which he seems to have maintained that the mechanism of the universe is one and the same throughout, modifying itself, or being modified by some vital element within, in an infinity of diverse ways.[207] Leibnitz’s famous idea, of making nature invariably work with the minimum of action, was seized by Maupertuis, expressed as the Law of Thrift, and made the starting-point of speculations that led directly to Holbach and the System of Nature.[208] The Loi d’Epargne evidently tended to make unity of all the forces of the universe the keynote or the goal of philosophical inquiry. At this time of his life, Diderot resisted Maupertuis’s theory of the unity of vital force in the universe, or perhaps we should rather say that he saw how open it was to criticism. His resistance has none of his usual air of vehement conviction. However that may be, the theory excited his interest, and fitted in with the train of meditation which his thoughts about the Encyclopædia had already set in motion, and of which the Pensées Philosophiques of 1746 were the cruder prelude.
The Thoughts on the Interpretation of Nature are, in form as in title, imitated from those famous Aphorismi de Interpretatione Naturæ et Regni Hominis, which are more shortly known to all men as Bacon’s Novum Organum.[209] The connection between the aphorisms is very loosely held. Diderot began by premising that he would let his thoughts follow one another under his pen, in the order in which the subjects came up in his mind; and he kept his word. Their general scope, so far as it is capable of condensed expression, may be described as a reconciliation between the two great classes into which Diderot found thinkers upon Nature to be divided; those who have many instruments and few ideas, and those who have few instruments and many ideas,—in other words, between men of science without philosophy, and philosophers without knowledge of experimental science.
In the region of science itself, again, Diderot foresees as great a change as in the relations between science and philosophy. “We touch the moment of a great revolution in the sciences. From the strong inclination of men’s minds towards morals, literature, the history of nature and experimental physics, I would almost venture to assert that before the next hundred years are over, there will not be three great geometers to be counted in Europe. This science will stop short where the Bernouillis, the Eulers, the Maupertuis, the Clairauts, the Fontaines, the D’Alemberts, the Lagranges have left it. They will have fixed the Pillars of Hercules. People will go no further.” Those who have read Comte’s angry denunciations of the perversions of geometry by means of algebra, and of the waste of intellectual force in modern analysis,[210] will at least understand how such a view as Diderot’s was possible. And no one will be likely to deny that, whether or not the pillars of the geometrical Hercules were finally set a hundred years ago, the great discoveries of the hundred years since Diderot have been, as he predicted, in the higher sciences. The great misfortune of France was that the supremacy of geometry coincided with the opening of the great era of political discussion. The definitions of Montesquieu’s famous book, which opened the political movement in literature, have been shown to be less those of a jurisconsult than of a geometer.[211] Social truths, with all their profound complexity, were handled like propositions in Euclid, and logical deductions from arbitrary premises were treated as accurate representations of real circumstance. The repulse of geometry to its proper rank came too late.
Comte always liberally recognised Diderot’s genius, and any reader of Comte’s views on the necessities of subjective synthesis will discern the germ of that doctrine in the following remarkable section: