described by a consummate judge as the most German of all the French.  And his style is deeply marked by that want of feeling for the exquisite, that dulness of edge, that bluntness of stroke, which is the common note of all German literature, save a little of the very highest.  In conversation we do not insist on constant precision of phrase, nor on elaborate sustension of argument.  Apostrophe is made natural by the semi-dramatic quality of the situation.  Even vehement hyperbole, which is nearly always a disfigurement in written prose, may become impressive or delightful, when it harmonises with the voice, the glance, the gesture of a fervid and exuberant converser.  Hence Diderot’s personality invested his talk, as happened in the case of Johnson and of Coleridge, with an imposing interest and a power of inspiration which we should never comprehend from the mere perusal of his writings.

His admirers declared his head to be the ideal head of an Aristotle or a Plato.  His brow was wide, lofty, open, gently rounded.  The arch of the eyebrow was full of delicacy; the nose of masculine beauty; the habitual expression of the eyes kindly and sympathetic, but as he grew heated in talk, they sparkled like fire; the curves of the mouth bespoke an interesting mixture of finesse, grace, and geniality.  His bearing was nonchalant enough, but there was naturally in the carriage of his head, especially when he talked with action, much dignity, energy, and nobleness.  It seemed as if enthusiasm were the natural condition for his voice, for his spirit, for every feature.  He was only truly Diderot when his thoughts had transported him beyond himself.  His ideas were stronger than himself; they swept him along without the power either to stay or to guide their movement.  “When I recall Diderot,” wrote one of his friends, “the immense variety of his ideas, the amazing multiplicity of his knowledge, the rapid flight, the warmth, the impetuous tumult of his imagination, all the charm and all the disorder of his conversation, I venture to liken his character to nature herself, exactly as he used to conceive her—­rich, fertile, abounding in germs of every sort, gentle and fierce, simple and majestic, worthy and sublime, but without any dominating principle, without a master and without a God."[21] Gretry, the musical composer, declares that Diderot was one of the rare men who had the art of blowing the spark of genius into flame; the first impulses stirred by his glowing imagination were of inspiration divine.[22]

Marmontel warns us that he who only knows Diderot in his writings, does not know him at all.  We should have listened to his persuasive eloquence, and seen his face aglow with the fire of enthusiasm.  It was when he grew animated in talk, and let all the abundance of his ideas flow freely from the source, that he became truly ravishing.  In his writings, says Marmontel with obvious truth, he never had the art of forming a whole, and this was because that first process of arranging everything in its place was too slow and too tiresome for him.  The want of ensemble vanished in the free and varied course of conversation.[23]