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]

We have to remember then that Diderot was in this respect of the
Socratic type, though he was unlike Socrates, in being the disseminator
of positive and constructive ideas. His personality exerted a decisive
force and influence. In reading the testimony of his friends, we think
of the young Aristides saying to Socrates: "I always made progress
whenever I was in your neighbourhood, even if I were only in the same
house, without being in the same room; but my advancement was greater if
I were in the same room with you, and greater still if I could keep my
eyes fixed upon you."[24] It has been well said that Diderot, like
Socrates, had about him a something daemonic. He was possessed, and so
had the first secret of possessing others. But then to reach excellence
in literature, one must also have self-possession; a double current of
impulse and deliberation; a free stream of ideas spontaneously obeying a
sense or order, harmony, and form. Eloquence in the informal discourse
of the parlour or the country walk did not mean in Diderot's case the
empty fluency and nugatory emphasis of the ordinary talker of
reputation. It must have been both pregnant and copious; declamatory in
form, but fresh and substantial in matter; excursive in arrangement, but
forcible and pointed in intention. No doubt, if he was a sage, he was
sometimes a sage in a frenzy. He would wind up a peroration by dashing
his nightcap passionately against the wall, by way of clencher to the
argument. Yet this impetuosity, this turn for declamation, did not
hinder his talk from being directly instructive. Younger men of the most
various type, from Morellet down to Joubert, men quite competent to
detect mere bombast or ardent vagueness, were held captive by the
cogency of his understanding. His writings have none of this compulsion.
We see the flame, but through a veil of interfused smoke. The expression
is not obscure, but it is awkward; not exactly prolix, but heavy,
overcharged, and opaque. We miss the vivid precision and the high
spirits of Voltaire, the glow and the brooding sonorousness of Rousseau,
the pomp of Buffon. To Diderot we go not for charm of style, but for a
store of fertile ideas, for some striking studies of human