rst words that presented
themselves to clothe it. But everywhere there is to be perceived the
cardinal principle of sound criticism--that a book is to be judged, not
according to arbitrary rules laid down _ex cathedra_ for the class of
books to which it is supposed to belong, but according to the scheme of
its author in the first place, and in the second to the general laws of
aesthetics; a science which, if the Germans named it, Diderot, by their
own confession, did much to create. Even more remarkable in this respect
than his book-criticisms are his _Salons_, criticisms of the biennial
exhibitions of pictures in Paris, also written for Grimm. There are nine
of these, ranging over a period of twenty-two years, and they have
served as models for more than a century. Diderot did not adopt the old
plan (as old as the Greeks) of mere description more or less elaborate
of the picture, nor the plan of dilating on its merely technical
characteristics, though, assisted by artist friends, he managed to
introduce a fair amount of technicalities into his writing. His method
is to take in the impression produced by the painting on his mind, and
to reproduce it with the associations and suggestions it has supplied.
Thus his criticisms are often extremely discursive, and some of his most
valuable reflections on matters at first sight quite remote from the
fine arts occur in these _Salons_. Of drama Diderot had a formal theory
which he illustrated by examples not quite so happy as his precepts.
This theory involved the practical substitution of what is called in
French _drame_ for the conventional tragedy and comedy, and it brought
the French theatre (or would have brought it if it had been adopted,
which it was not until 1830) much nearer to the English than it had
been. Diderot was moreover an enthusiastic admirer of English novels,
and especially of Richardson and Sterne, partly no doubt because the
sentimentalism which characterised them coincided with his own
_sensibilite_, but also (it is fair to believe) because of their freedom
from the artificiality and the strict observance of models which
pervaded all branches of literature in France. Of poetry proper we have
little formal criticism from Diderot. His own verses are few, and of no
merit, nor was the poetry of the time at all calculated to excite any
enthusiasm in him. But the aesthetic tendency which in other ways he
expressed, and which he was the first to express, was that