n was the obvious
aspect of Socrates, his ethics, and above all the ethical teaching
which was expressed, not so {157} much in abstract ideas, as in the
life and personality of the master. Both this life and this teaching
might be summed up in the thought that virtue is the sole end of life,
that, as against virtue, all else in the world, comfort, riches,
learning, is comparatively worthless. It is this, then, that virtue is
the sole end of life, which forms the point of agreement between all
the three semi-Socratic schools. We have now to see upon what points
they diverge from one another.

If virtue is the sole end of life, what precisely is virtue? Socrates
had given no clear answer to this question. The only definition he had
given was that virtue is knowledge, but upon examination it turns out
that this is not a definition at all. Virtue is knowledge, but
knowledge of what? It is not knowledge of astronomy, of mathematics,
or of physics. It is ethical knowledge, that is to say, knowledge of
virtue. To define virtue as the knowledge of virtue is to think in a
circle, and gets us no further in the enquiry what virtue is. But
Socrates, as a matter of fact, did not think in a circle. He did not
mean that virtue is knowledge, although his doctrine is often,
somewhat misleadingly, stated in that form. What he meant was--quite a
different thing--that virtue _depends upon_ knowledge. It is the first
condition of virtue. The principle, accurately stated, is, not that
virtue is the knowledge of virtue, which is thinking in a circle, but
that virtue depends upon the knowledge of virtue, which is quite
straight thinking. Only if you know what virtue is can you be
virtuous. Hence we have not here any definition of virtue, or any
attempt to define it. We are still left with the question, "what is
virtue?" unanswered.

{158}

No doubt this was due in part to the unmethodical and unsystematic
manner in which Socrates developed his thought, and this, in its turn,
was due to his conversational style of philosophizing. For it is not
possible to develop systematic thinking in the course of casual
conversations. But in part, too, it was due to the very universality
of the man's genius. He was broad enough to realize that it is not
possible to tie down virtue in any single narrow formula, which shall
serve as a practical receipt for action in all the infinitely various
circumstances of life. So that, in spite of the fact that his wh