hical doctrine of the necessity of suspending or refusing our
assent from want of a criterion of judgment led by a natural transition
to the moral doctrine that virtue and happiness consist in perfect
quiescence or freedom from all mental perturbation. This doctrine, it is
said, he had learned in India from the Brahmans, whither he had been in
the expedition of Alexander. On his return to Europe he taught these
views in his school at Elis; but Greek philosophy, in its own order of
advancement, was verging on the discovery of these conclusions.

[Sidenote: Secondary analysis of ethical philosophy.]

The Sceptical school was thus founded on the assertion that man can
never ascertain the true among phenomena, and therefore can never know
whether things are in accordance or discordance with their appearances,
for the same object appears differently to us in different positions and
at different times. Doubtless it also appears differently to various
individuals. Among such appearances, how shall we select the true one,
and, if we make a selection, how shall we be absolutely certain that we
are right? Moreover, the properties we impute to things, such as colour,
smell, taste, hardness, and the like, are dependent upon our senses; but
we very well know that our senses are perpetually yielding to us
contradictory indications, and it is in vain that we expect Reason to
enable us to distinguish with correctness, or furnish us a criterion of
the truth. The Sceptical school thus made use of the weapon which the
Sophists had so destructively employed, directing it, however, chiefly
against ethics. But let us ascend a step higher. If we rely upon Reason,
how do we know that Reason itself is trustworthy? Do we not want some
criterion for it? And, even if such a criterion existed, must we not
have for it, in its turn, some higher criterion? The Sceptic thus
justified his assertion that to man there is no criterion of truth.

[Sidenote: The doctrines of Pyrrho.]

[Sidenote: No certainty in knowledge.]

In accordance with these principles, the Sceptics denied that we can
ever attain to a knowledge of existence from a knowledge of phenomena.
They carried their doubt to such an extreme as to assert that we can
never know the truth of anything that we have asserted, no, not even the
truth of this very assertion itself. "We assert nothing," said they;
"no, not even that we assert nothing." They declared that the system of
induction is at