t, but it is less
prominent, owing to his greater acquaintance with the individual matters
which he handled. His contributions to definite philosophical literature
are not unimportant. He began by an 'Essay on Merit and Virtue,' 1745,
imitated from Shaftesbury, and by some more original _Pensees
Philosophiques_. These pieces were followed by _La Promenade du
Sceptique_, written somewhat in the fashion of Berkeley's _Alciphron_,
and by some minor treatises, the most important of which are the
_Lettres sur les Sourds et Muets_, and by the already mentioned _Lettre
sur les Aveugles_, which led to his imprisonment, with some 'Thoughts on
the Interpretation of Nature.' A singular and characteristic book
containing not a few acute but fantastic ideas is _Le Reve de
D'Alembert_, which, like an elaborate criticism on Helvetius' _De
l'Homme,_ was not printed during Diderot's life. The _Essai sur les
Regnes de Claude et de Neron_ was one of the latest of Diderot's works,
and is a kind of historico-philosophical disquisition. The last piece of
any importance which is included in the philosophical works of Diderot
is an extensive scheme for a Russian university.

The characteristics of Diderot's philosophical works are the same as the
characteristics of those other works of his which have been noticed, and
his general position as a writer may well be considered here. There has
seldom been an author who was more fertile in ideas. It is impossible to
name a subject which Diderot has not treated, and hardly possible to
name one on which he has not said striking and memorable things. The
peculiarity of his mind was, that it could adjust itself, with hardly
any effort, to any subject presented to it, grasp that subject and
express thoughts on it in a novel and effective manner. He had moreover,
what some other men of his century, notably Voltaire, lacked, a vast
supply of positive information on the subjects with which he dealt, and
an entire independence of conventional points of view in dealing with
them. This independence was in some respects pushed to an unfortunate
length, exposing him (whether deservedly or not, is an exceedingly
difficult point to resolve) to the charge of atheism, and (beyond all
doubts deservedly) to the charge of wilful disregard of the accepted
decencies of language. Another and very serious fault, arising partly
from temperament and partly from circumstances, was the want of needful
pains and deliberation wh