not be in robust health; and should have known what illness is in his own person. But the judge ought to have had no similar experience of evil; he is to be a good man who, having passed his youth in innocence, became acquainted late in life with the vices of others. And therefore, according to Plato, a judge should not be young, just as a young man according to Aristotle is not fit to be a hearer of moral philosophy. The bad, on the other hand, have a knowledge of vice, but no knowledge of virtue. It may be doubted, however, whether this train of reflection is well founded. In a remarkable passage of the Laws it is acknowledged that the evil may form a correct estimate of the good. The union of gentleness and courage in Book ii. at first seemed to be a paradox, yet was afterwards ascertained to be a truth. And Plato might also have found that the intuition of evil may be consistent with the abhorrence of it. There is a directness of aim in virtue which gives an insight into vice. And the knowledge of character is in some degree a natural sense independent of any special experience of good or evil.