When his imprisonment had lasted three months Diderot, at the angry urging of the booksellers of Paris, was released. In 1745 one of those booksellers, Le Breton, had suggested to him ‘the scheme of a book that should be all books.’ Enterprising England had been first in the field. To Francis Bacon belongs the honour of having originated the idea of an Encyclopædia. Chambers, an Englishman, first worked out that idea. It was a French translation of Chambers that Le Breton took to Diderot, and it was Diderot who breathed upon it the breath of life. That this knavish bookseller’s choice should have fallen out of all men upon him, might have inclined even so whole-hearted a sceptic as Denis himself to believe in an Intelligence behind the world. He was hungry and poor, and _must_ have work that would bring him bread. There were indeed thousands of persons in that position; but out of those thousands there was only one with the hot, sanguine courage to undertake so risky a scheme, with the ‘fiery patience’ to work it in the face of overwhelming odds, and with the exuberant genius to make it the mighty masterpiece it became. Diderot saw its possibilities at once. In another second, as it were, he saw all he could himself do, and all he could not do. He could write about most things. He could study the trades and industries of France, if it took him thirty years of labour, of which the mere thought would daunt most men; by giving their history he could glorify for ever those peaceful arts which make a nation truly great and happy. He could write on Gallantry, on Genius, on Libraries, on Anagrams. For his fertile spirit scarcely any subject was too great or too small. Against intolerance he could bring to bear ‘the concentrated energy of a profound conviction.’ Religion itself he could attack in so far as it interfered with men’s liberty; and miracle he must attack, because, in the words of Voltaire, ‘Men will not cease to be persecutors till they have ceased to be absurd.’ If he had, just to appease the authorities, and to give the book a chance of a hearing, to truckle here and there to prejudice and superstition, well, Diderot could lie as heartily and as cheerfully as he did all things. But the inexact schoolboy of Harcourt College was no mathematician, and knew his limitations. With the freemasonry of genius he saw in a single flashing glance that d’Alembert was the man to share with him the parentage of this wonderful child. He stormed the calm savant in his attic above the glazier’s shop, overwhelmed, prayed, pressed, bewitched him, and with ‘his soul in his eyes and his lips’ woke in d’Alembert’s quiet breast an enthusiasm which was at least some reflex of his own.