Seneca, answered from the texts and cited to the page.
The four are justice, bravery, restraint, and — underlying and unifying all three — that single virtue which renders the soul straight and unswerving, which we may call prudence or right reason.1 Each of these is not a separate living creature dwelling in the soul alongside the others, but a particular attitude, a state, a kind of power, of the one soul.2
The soul transforms itself into various likenesses without becoming a different kind of thing each time it acts differently; justice is the soul maintaining itself in a certain posture, bravery another posture of the same soul.3 They coexist simultaneously — you do not lose justice when bravery is present, nor does restraint depart when justice acts.4
What matters philosophically is that they are equal in dignity, because underlying them all is a single virtue: right reason, which is nothing else than a portion of the divine spirit set in a human body.5 Since reason is divine and the good in no case lacks reason, the good in every case is divine — and between divine things there is no distinction, hence no inequality between the virtues themselves.6
The brave man storming an enemy's stronghold and the patient man enduring a siege possess equal virtue, because in both the soul is great, whether relaxed and cheerful or combative and braced for action.7 And the measure of a man is precisely here: not how many acres he ploughs, not how much money he has at interest, not how costly his couch — but how good he is, which is to say how well his reason is ordered and adapted to what his nature has willed.8 That is what virtue is; that is what we mean by the honourable; and it is man's unique good.9
underlying them all is a single virtue—that which renders the soul straight and unswerving.Moral Letters to Lucilius
Justice is really a state, a kind of power, of the soul; and this same soul is transformed into various likenesses and does not become a different kind of living thing as often as it acts differently.Moral Letters to Lucilius
Justice is really a state, a kind of power, of the soul; and this same soul is transformed into various likenesses and does not become a different kind of living thing as often as it acts differently.Moral Letters to Lucilius
This would be possible if Bravery were absent when Justice was present, and if Restraint were absent when Bravery was present; as the case stands now, all the virtues exist at the same time.Moral Letters to Lucilius
Reason, however, is nothing else than a portion of the divine spirit set in a human body.Moral Letters to Lucilius
If reason is divine, and the good in no case lacks reason, then the good in every case is divine. And furthermore, there is no distinction between things divine; hence there is none between goods, either.Moral Letters to Lucilius
Great is Scipio when he invests Numantia...Great also are the souls of the defenders...In like manner, the other virtues are also equal as compared with one another.Moral Letters to Lucilius
it is not pertinent to the question to know how many acres he ploughs, how much money he has out at interest...but how good he is. He is good, however, if his reason is well-ordered and right and adapted to that which his nature has willed.Moral Letters to Lucilius
It is this that is called virtue; this is what we mean by 'honourable'; it is man's unique good.Moral Letters to Lucilius