s over the many ramifications of his central idea.
We can only notice that Diderot had a foot on the track along which
Lessing afterwards made such signal progress. The reader who cares to
measure the advantage of Lessing's more serious and concentrated
attention to his subject, may compare the twelfth chapter of _Laocoeon_
with Diderot's criticism on Doyen's painting of the Battle between
Diomede and Aeneas.[65] As we see how near Diderot came to the real and
decisive truths of all these matters, and yet how far he remains from
the full perception of what a little consecutive study must have
revealed to his superior genius, we can only think painfully of his
avowal--"I have not the consciousness of having employed the half of my
strength: _jusqu'a present je n'ai que baguenaude_."

[65] _Salon de 1761_; _Oeuv._, v. 140.

On the great art of music Diderot has said little that is worth
attending to. Bemetzrieder, a German musician, who taught Diderot's
daughter to play on the clavecin, wrote an elementary book called
Lessons on the Clavecin and Principles of Harmony. This is pronounced by
the modern teachers to be not less than contemptible. Diderot, however,
with his usual boundless good nature, took the trouble to set the book
in a series of dialogues, in which teacher, pupil, and a philosopher
deal in all kinds of elaborate amenities, and pay one another many
compliments. It reminds one of the old Hebrew grammar which is couched
in the form of Conversations with a Duchess--"Your Grace having kindly
condescended to approve of the plan that I have sketched. All this your
Grace probably knows already, but your Grace has probably never
attempted," and so forth.

The unwise things that men of letters have written from a good-natured
wish to help their friends, are not so numerous that we need be afraid
of extending to them a good-natured pardon. The beauty of Diderot's
Salons is remarkable enough to cover a multitude of sins in other arts.
There are few other compositions in European literature which show so
well how criticism of art itself may become a fine art.

CHAPTER IV.

ST. PETERSBURG AND THE HAGUE.

"What would you say of the owner of an immense palace, who should spend
all his life in going up from the cellars to the attics, and going down
from attics to cellar, instead of sitting quietly in the midst of his
family? That is the image of the traveller." Yet Diderot, whose words
these are, resolve