a book that should be all books. On his lips, sciences were light and
life. It was more than speech, it was creation. One would have said that
he had made these sciences, and was still at work, adding, extending,
fertilising, ever engendering. The effect was incredible. D'Aguesseau, a
moment above himself, forgot the old man, received the infection of
genius, and became great with the greatness of the other. He had faith
in the young man, and protected the Encyclopaedia."[98]

A fresh privilege was procured (Jan. 21, 1746), and as Le Breton's
capital was insufficient for a project of this magnitude, he invited
three other booksellers to join him, retaining a half share for himself,
and allotting the other moiety to them. As Le Breton was not strong
enough to bear the material burdens of producing a work on so gigantic a
scale as was now proposed, so Diderot felt himself unequal to the task
of arranging and supervising every department of a book that was to
include the whole circle of the sciences. He was not skilled enough in
mathematics, nor in physics, which were then for the most part
mathematically conceived. For that province, he associated with himself
as an editorial colleague one of the most conspicuous and active members
of the philosophical party. Of this eminent man, whose relations with
Diderot were for some years so intimate, it is proper that we should say
something.

D'Alembert was the natural son of Madame de Tencin, by whom he had been
barbarously exposed immediately after his birth. "The true ancestors of
a man of genius," says Condorcet finely upon this circumstance, "are the
masters who have gone before him, and his true descendants are disciples
that are worthy of him." He was discovered on a November night in the
year 1717, by the beadle, in a nearly dying condition on the steps of
the church of St. John the Round, from which he afterwards took his
Christian name. An honest woman of the common people, with that personal
devotion which is less rare among the poor than among the rich, took
charge of the foundling. The father, who was an officer of artillery and
brother of Destouches, the author of some poor comedies, by and by
advanced the small sums required to pay for the boy's schooling.
D'Alembert proved a brilliant student. Unlike nearly every other member
of the encyclopaedic party, he was a pupil not of the Jesuits but of
their rivals. The Jansenists recognised the keenness and force of their