Without a virtuous aim, there is no such thing as Prudence: there is nothing but cleverness degenerating into cunning; while virtue without virtuous prudence is nothing better than a mere instinct, liable to be misguided in every way (XII.).
There is one more difficulty to be cleared up respecting virtue.

All our dispositions; and therefore all our ethical excellences, come to us in a certain sense by nature; that is, we have from the moment of birth a certain aptitude for becoming temperate, courageous, just, &c.

But these natural aptitudes or possessions [Greek: physikai hexeis] are something altogether distinct from the ethical excellences proper, though capable of being matured into them, if intellect and prudence be superadded.

Sokrates was mistaken in resolving all the virtues into prudence; but he was right in saying that none of them can exist without prudence.

The virtues ought to be defined as, not merely ethical dispositions _according_ to right reason, but ethical dispositions _along with_ right reason or prudence (_i.e._, prudence is an ever present co-efficient).