The true and only good then was identical with what the Greeks called
'the beautiful' and what we call 'the right'. To say that a thing was
right was to say that it was good, and conversely to say that it was
good was to say that it was right; this absolute identity between the
good and the right and, on the other hand, between the bad and wrong,
was the head and front of the Stoic ethics. The right contained in
itself all that was necessary for the happy life, the wrong was the
only evil, and made men miserable whether they knew it or not.

As virtue was itself the end, it was of course choiceworthy in and
for itself, apart from hope or fear with regard to its consequences.
Moreover, as being the highest good, it could admit of no increase
from the addition of things indifferent. It did not even admit of
increase from the prolongation of its own existence, for the question
was not one of quantity, but of quality. Virtue for an eternity was
no more virtue, and therefore no more good, than virtue for a moment.
Even so one circle was no more round than another, whatever you might
choose to make its diameter, nor would it detract from the perfection
of a circle if it were to be obliterated immediately in the same dust
in which it had been drawn.

To say that the good of men lay in virtue was another way of saying
that it lay in reason, since virtue was the perfection of reason.

As reason was the only thing whereby Nature had distinguished man
from other creatures, to live the rational life was to follow Nature.

Nature was at once the law of God and the law for man. For by the
nature of anything was meant, not that which we actually find it to
be, but that which in the eternal fitness of things it was obviously