The other error is
that some people devote too much industry and too
deep study to matters that are obscure and difficult
and useless as well.
If these errors are successfully avoided, all the
labour and pains expended upon problems that are
morally right and worth the solving will be fully
rewarded. Such a worker in the field of astronomy,
for example, was Gaius Sulpicius, of whom we have
heard; in mathematics, Sextus Pompey, whom I
have known personally; in dialectics, many; in civil
law, still more. All these professions are occupied
with the search after truth; but to be drawn by
study away from active life is contrary to moral
duty. For the whole glory of virtue is in activity;
activity, however, may often be interrupted, and
many opportunities for returning to study are opened.
Besides, the working of the mind, which is never at
rest, can keep us busy in the pursuit of knowledge
even without conscious effort on our part. Moreover, all our thought and mental activity will be
devoted either to planning for things that are morally
right and that conduce to a good and happy life, or
to the pursuits of science and learning.
With this we close the discussion of the first
source of duty.