ich characterises most of Diderot's work. That
work is extremely voluminous, and even as it is, we have not anything
like the whole of it in a collected form. Indeed, by far the larger part
was never given to the world by the author himself in any deliberate or
finished shape, and much of what he did publish was the result of mere
improvisation. The consequence is, that Diderot is accused, not without
truth, of having written good passages, but no good book, and that a
full appreciation of his genius is only to be obtained by a most
laborious process of wading through hundreds and thousands of pages of
very inferior work. The result of that process, however, is never likely
to be doubtful in the case of competent examiners. It is the conviction
that Diderot ranks in point of originality and versatility of thought
among the most fertile thinkers of France, and in point of felicity and
idiosyncrasy of expression, among the most remarkable of her writers.

[Sidenote: D'Alembert.]

His coadjutor during the earlier part of his great work was a man
curiously different from himself. Diderot was a rapid and careless
writer, devoted to general society and conversation, interested in
everything that was brought to his notice, passionate, unselfish,
frequently extravagant. Jean le Rond d'Alembert (who was really an
illegitimate son of Madame de Tencin by an uncertain father) was an
extraordinarily careful writer, a man of retired habits, reserved,
self-centred and phlegmatic. He was born in 1717, was exposed on the
steps of a church, but was brought up carefully by a foster-mother of
the lower classes, to whom he was consigned by the authorities, and had
a not insufficient annuity settled upon him by his supposed father. He
was educated at the College Mazarin, and early showed great aptitude for
mathematics, in which equally with literature he distinguished himself
in after years. He was elected a member of the Academy of Sciences as
early as at the age of four-and-twenty. After he had joined Diderot, he
wrote a preliminary discourse for the Encyclopaedia--a famous and
admirable sketch of the sciences--besides many articles. Of these, one
on Geneva brought the book into more trouble than almost any other
contribution, though D'Alembert was equally moderate as a thinker and as
a writer. D'Alembert, as has been said, retired from the work after this
storm, being above all things solicitous of peace and quietness. His
refusals of th