ates
had used against the Sophists on physical questions, for an actual
scepticism on points connected with morals, he fell into the opposite
extreme, and declared, first, that nothing could be known, and
therefore, secondly, nothing should be maintained.[151]

Whatever were his private sentiments (for some authors affirm his
esoteric doctrines to have been dogmatic[152]), he brought forward these
sceptical tenets in so unguarded a form, that it required all his
argumentative powers, which were confessedly great, to maintain them
against the obvious objections which were pressed upon him from all
quarters. On his death, therefore, as might have been anticipated, his
school was deserted for those of Zeno and Epicurus; and during the lives
of Lacydes, Evander, and Hegesinus, who successively filled the Academic
chair, being no longer recommended by the novelty of its doctrines,[153]
or the talents of its masters, it became of little consideration amid
the wranglings of more popular philosophies. Carneades,[154] therefore,
who succeeded Hegesinus, found it necessary to use more cautious and
guarded language; and, by explaining what was paradoxical, by
reservations and exceptions, in short, by all the arts which an acute
and active genius could suggest, he contrived to establish its
authority, without departing, as far as we have the means of judging,
from the principle of universal scepticism which Arcesilas had so
pertinaciously advocated.[155]

The New Academy,[156] then, taught with Plato, that all things in their
own nature were fixed and determinate; but that, through the
constitution of the human mind, it was impossible _for us_ to see them
in their simple and eternal forms, to separate appearance from reality,
truth from falsehood.[157] For the conception we form of any object is
altogether derived from and depends on the sensation, the impression, it
produces on our own minds ([Greek: pathos energeias, phantasia]). Reason
does but deduce from premisses ultimately supplied by sensation. Our
only communication, then, with actual existences being through the
medium of our own impressions, we have no means of ascertaining the
correspondence of the things themselves with the ideas we entertain of
them; and therefore can in no case be certain of the truthfulness of our
senses. Of their fallibility, however, we may easily assure ourselves;
for in cases in which they are detected contradicting each other, all
cannot be c