of optimism, though he had previously favored it.

[Footnote 1: David Friedrich Strauss, _Voltaire, sechs Vortraege_, 1870.]

%2. Theoretical and Practical Sensationalism.%

We turn next from the popular introduction and dissemination of Locke's
doctrines, which left their contents unchanged, to their principiant
development by the French sensationalists. Condillac (1715-80) always
thinks of his work as a completion of Locke's, whose _Essay_ he held not to
have gone down to the final root of the cognitive process. Locke did not
go far enough, Condillac thinks, in his rejection of innate elements; he
failed to trace out the origin of perception, reflection, cognition, and
volition, as also the relation between the external senses, the internal
sense, and the combining intellect, which he discussed as separate sources,
the two former of particular, and the last of complex, ideas; in short,
he omitted to inquire into the origin of the first function of the soul.
Berkeley was right in feeling that a simplification was needed here; but by
erroneously reducing outer perception to inner perception, he reached the
absurd conclusion of denying the external world. The true course is just
the opposite of this--the one already taken by the Bishop of Cork, Peter
Browne (died 1735; _The Procedure, Extent, and Limits of the Human
Understanding_, 1728): understanding and reflection must be reduced to
sensation. All psychical functions are transformed sensations. The soul has
only one original faculty, that of sensation; all the others, theoretical
and practical alike, are acquired, _i.e._, they have gradually developed
from the former. Condillac is related to Locke as Fichte to Kant; in
the former case the transition is mediated by Browne, in the latter
by Reinhold. Each crowns the work of his predecessor with a unifying
conclusion; each demands and offers a genetic psychology which finds the
origin of all the spiritual functions--from sensation and feelings of
pleasure and pain up to rational cognition and moral will--in a single
fundamental power of the soul. But there is a great difference, materially
as well as formally, between these kindred undertakings, a difference
corresponding to that between Locke's empiricism and Kant's idealism.
The idea of ends, which controls the course of thought in Fichte as in
Leibnitz, is entirely lacking in Condillac; that which is first in time,
sensation, is for the Science of Knowledge and the