these ideas were the direct source of the great undertaking of Diderot's
life. He is said to have read little and to have meditated much--the
right process for the few men of his potent stamp. The work which he had
to do for bread was of the kind that crushes anything short of the
strongest faculty. He composed sermons. A missionary once ordered
half-a-dozen of them for consumption in the Portuguese colonies, and
paid him fifty crowns apiece, which Diderot counted far from the worst
bargain of his life. All this was beggarly toil for a man of genius, but
Diderot never took the trouble to think of himself as a man of genius,
and was quite content with life as it came. If he found himself
absolutely without food and without pence, he began moodily to think of
abandoning his books and his pen, and of complying with the wishes of
his father. A line of Homer, an idea from the Principia, an interesting
problem in algebra or geometry, was enough to restore the eternally
invincible spell of knowledge. And no sooner was this commanding
interest touched, than the cloud of uncomfortable circumstance vanished
from before the sun, and calm and serenity filled his spirit.

Montesquieu used to declare that he had never known a chagrin which half
an hour of a book was not able to dispel. Diderot had the same fortunate
temper.

Yet Diderot was not essentially a man of books. He never fell into the
characteristic weakness of the follower of letters, by treating books as
ends in themselves, or placing literature before life. Character,
passion, circumstance, the real tragi-comedy, not its printed shadow
and image, engrossed him. He was in this respect more of the temper of
Rousseau, than he was like Voltaire or Fontenelle. "Abstraction made,"
he used to say, "of my existence and of the happiness of my fellows,
what does the rest of nature matter to me?" Yet, as we see, nobody that