A quiet life, a cipher in the crowd,
Sharing the common fortune. . .
Restless, aspiring, busy men of action. . .
”1 For people seek their own good, and suppose that it is right to do so. Hence this belief has caused the word ‘prudent’ to mean those who are wise in their own interest. Yet probably as a matter of fact a man cannot pursue his own welfare without Domestic Economy and even Politics. Moreover, even the proper conduct of one's own affairs is a difficult problem, and requires consideration. [5]
A further proof of what has been said2 is, that although the young may be experts in geometry and mathematics and similar branches of knowledge, we do not consider that a young man can have Prudence. The reason is that Prudence includes a knowledge of particular facts, and this is derived from experience, which a young man does not a possess; [6] for experience is the fruit of years.3 (One might indeed further enquire why it is that, though a boy may be a mathematician, he cannot be a metaphysician or a natural philosopher.4 Perhaps the answer is that Mathematics deals with abstractions, whereas the first principles of Metaphysics and Natural Philosophy are derived from experience: the young can only repeat them