Virtue having been purified from all the dross of the emotions, came out as something purely intellectual, so that the Stoics agreed with the Socratic conception that virtue is knowledge. They also took on from Plato the four cardinal virtues of Wisdom, Temperance, Courage, and Justice, and defined them as so many branches of knowledge. Against these were set four cardinal vices of Folly, Intemperance, Cowardice, and Injustice. Under both the virtues and vices there was an elaborate classification of specific qualities. But notwithstanding the care with which the Stoics divided and subdivided the virtues, virtue, according to their doctrine, was all the time one and indivisible. For virtue was simply reason and reason, if it were there, must control every department of conduct alike. 'He who has one virtue has all,' was a paradox with which the Greek thought was already familiar. But Chrysippus went beyond this, declaring that he who displayed one virtue did thereby display all. Neither was the man perfect who did not possess all the virtues, nor was the act perfect which did not involve them all. Where the virtues differed from one another was merely in the order in which they put things. Each was primarily itself, secondarily all the rest. Wisdom had to determine what it was right to do, but this involved the other virtues. Temperance had to impart stability to the impulses, but how could the term 'temperate' be applied to a man who deserted his post through cowardice, or who failed to return a deposit through avarice, which is a form of injustice, or yet to one who misconducted affairs through rashness, which falls under folly? Courage had to face dangers and difficulties, but it was not courage unless its cause were just. Indeed one of the ways in which courage was defined was a virtue fighting on behalf of justice. Similarly justice put first the assigning to each man his due, but in the act of doing so had to bring in the other virtues. In short, it was the business of the man of virtue to know and to do what ought to be done, for what ought to be done implied wisdom in choice, courage in endurance, justice in assignment and temperance in abiding by ones conviction. One virtue never acted by itself, but always on the advice of a committee. The obverse to this paradox--He who has one vice has all vices--was a conclusion which the Stoics did not shrink from drawing. One might lose part of one's Corinthian ware and still retain the rest, but to lose one virtue--if virtue could be lost--would be to lose all along with it.