so it shall suffice to sift those which are most generally current, or
are thought to have some reason in them.

[Sidenote: 1095b] And here we must not forget the difference between
reasoning from principles, and reasoning to principles: for with good
cause did Plato too doubt about this, and inquire whether the right road
is from principles or to principles, just as in the racecourse from the
judges to the further end, or _vice versa_.

Of course, we must begin with what is known; but then this is of two
kinds, what we _do_ know, and what we _may_ know: perhaps then as
individuals we must begin with what we _do_ know. Hence the necessity
that he should have been well trained in habits, who is to study, with
any tolerable chance of profit, the principles of nobleness and justice
and moral philosophy generally. For a principle is a matter of fact,
and if the fact is sufficiently clear to a man there will be no need in
addition of the reason for the fact. And he that has been thus trained
either has principles already, or can receive them easily: as for him
who neither has nor can receive them, let him hear his sentence from
Hesiod:

He is best of all who of himself conceiveth all things;
Good again is he too who can adopt a good suggestion;
But whoso neither of himself conceiveth nor hearing from
another
Layeth it to heart;--he is a useless man.

[Sidenote: V] But to return from this digression.

Now of the Chief Good (_i.e._ of Happiness) men seem to form their