These contributions to what was then the most popular of the sciences brought him fame, and fame brought him its usual distractions. As soon as a writer has shown himself the possessor of gifts that may be of value to society, then society straightway sets to work to seduce and hinder him from diligently exercising them. D'Alembert resisted these influences steadfastly. His means were very limited, yet he could never be induced to increase them at the cost either of his social independence or of his scientific pursuits. He lived for forty years under the humble roof of the poor woman who had treated him as a son. "You will never be anything better than a philosopher," she used to cry reproachfully, "and what is a philosopher? 'Tis a madman who torments himself all his life, that people may talk about him when he is dead." D'Alembert zealously adhered to his destination. Frederick the Great vainly tempted him by an offer of the succession to Maupertuis as president of the Academy of Berlin. Although, however, he declined to accept the post, he enjoyed all its authority and prerogative. Frederick always consulted him in filling up vacancies and making appointments. It is a magnanimous trait in D'Alembert's history that he should have procured for Lagrange a position and livelihood at Berlin, warmly commending him as a man of rare and superior genius, although Lagrange had vigorously opposed some of his own mathematical theories. Ten years after Frederick's offer, the other great potentate of the north, Catherine of Russia, besought him to undertake the education of the young grand duke, her son. But neither urgent flatteries and solicitations under the imperial hand, nor the munificent offer of a hundred thousand francs a year, availed to draw him away from his independence and his friends. The great Frederick used to compare him to one of those oriental monarchs, who cherish a strict seclusion in order to enhance their importance and majesty. He did not refuse a pension of some fifty pounds a year from Berlin, and the same amount was bestowed upon him from the privy purse at Versailles. He received a small annual sum in addition from the Academy.
Though the mathematical sciences remained the objects of his special study, D'Alembert was as free as the other great men of the encyclopædic school from the narrowness of the pure specialist. He naturally reminds us of the remarkable saying imputed to Leibnitz, that he only attributed importance to science, because it enabled him to speak with authority in philosophy and religion. His correspondence with Voltaire, extending over the third quarter of the century, is the most instructive record that we possess of the many-sided doings of that busy time. His series of éloges on the academicians who died between 1700 and 1772 is one of the most interesting works in the department of literary history. He paid the keenest attention to the great and difficult art of writing. Translations from Tacitus, Bacon, and Addison, show his industry in a useful practice. A long collection of synonyms bears witness to his fine discrimination in the use of words. And the clearness, precision, and reserved energy of his own prose mark the success of the pains that he took with style. He knew the secret. Have lofty sentiments, he said, and your manner of writing will be firm and noble.[100] Yet he did not ignore the other side and half of the truth, which is expressed in the saying of another important writer of that day—By taking trouble to speak with precision, one gains the habit of thinking rightly (Condillac).
Like so many others to whom literature owes much, D'Alembert was all his life fighting against bad health. Like Voltaire and Rousseau, he was born dying, and he remained delicate and valetudinarian to the end. He had the mental infirmities belonging to his temperament. He was restless, impatient, mobile, susceptible of irritation. When the young Mademoiselle Phlipon, in after years famous as wife of the virtuous Roland, was taken to a sitting of the Academy, she was curious to see the author of the Preliminary Discourse to the Encyclopædia, but his small face and sharp thin voice made her reflect with some disappointment, that the writings of a philosopher are better to know than his mask.[101] In everything except zeal for light and emancipation, D'Alembert was the opposite of Diderot. Where Diderot was exuberant, prodigal, and disordered, D'Alembert was a precisian. Difference of temperament, however, did not prevent their friendship from being for many years cordial and intimate. When the Encyclopædia was planned, it was to D'Alembert, as we have said, that Diderot turned for aid in the mathematical sciences, where his own knowledge was not sufficiently full nor well grounded. They were in strong and singular agreement in their idea of the proper place and function of the man of letters. One of the most striking facts about their alliance, and one of the most important facts in the history of the Encyclopædia, is that henceforth the profession of letters became at once definite and independent. Diderot and D'Alembert both of them remained poor, but they were never hangers-on. They did not look to patrons, nor did they bound their vision by Versailles. They were the first to assert the lawful authority of the new priesthood. They revolted deliberately and in set form against the old system of suitorship and protection. "Happy are men of letters," wrote D'Alembert, "if they recognise at last that the surest way of making themselves respectable is to live united and almost shut up among themselves; that by this union they will come, without any trouble, to give the law to the rest of the nation in all affairs of taste and philosophy; that the true esteem is that which is awarded by men who are themselves worthy of esteem. … As if the art of instructing and enlightening men were not, after the too rare art of good government, the noblest portion and gift in human reach."[102]
This consciousness of the power and exaltation of their calling, which men of letters now acquired, is much more than the superficial fact which it may at first seem to be. It marked the rise of a new teaching order and the supersession of the old. The highest moral ideas now belonged no longer to the clergy, but to the writers; no longer to official Catholicism, but to that fertilising medley of new notions about human knowledge and human society which then went by the name of philosophy. What is striking is that the ideas sown by philosophy became eventually the source of higher life in Catholicism. If the church of the revolution showed something that we may justly admire, it was because the encyclopædic band had involuntarily and inevitably imparted a measure of their own clearsightedness, fortitude, moral energy, and spirit of social improvement, to a church which was, when they began their work, an abominable burden on the spiritual life of the nation. If the Catholicism of Chateaubriand, of Lamennais, of Montalembert, was a different thing from the Catholicism of a Dubois, or a Rohan, from the vile corruptions of the Jesuits and the grovelling superstitions of the later Jansenists, it was the execrated freethinkers whom the church and mankind had to thank for the change. The most enlightened Catholic of to-day ought to admit that Voltaire, Diderot, Rousseau, were the true reformers of his creed. They supplied it with ideas which saved it from becoming finally a curse to civilisation. It was no Christian prelate, but Diderot who burst the bonds of a paralysing dogma by the magnificent cry, Détruisez ces enceintes qui rétrécissent vos idées! Elargissez Dieu![103] We see the same phenomenon in our own day. The Christian churches are assimilating as rapidly as their formula will permit, the new light and the more generous moral ideas and the higher spirituality of teachers who have abandoned all churches, and who are systematically denounced as enemies of the souls of men. Sic vos non vobis mellificatis apes! These transformations of religion by leavening elements contributed from a foreign doctrine, are the most interesting process in the history of truth.
The Encyclopædia became a powerful engine for aiding such a transformation. Because it was this, and because it rallied all that was then best in France round the standard of light and social hope, we ought hardly to grudge time or pains to its history.