Book 6: The Intellectual Virtues.
Chapter 8: Prudence compared with statesmanship and other forms of knowledge.
And in fact statesmanship and prudence are the same faculty, though they are differently manifested.
Of this faculty in its application to the state the supreme form is the legislative faculty, but the special form which deals with particular cases is called by the generic name statesmanship. The field of the latter is action and deliberation; for a decree directly concerns action, as the last link in the chain. And on this account those engaged in this field are alone said to be statesmen, for they alone act like handicraftsmen.
But it is when applied to the individual and to one’s own affairs that this faculty is especially regarded as prudence, and this is the form which receives the generic name prudence or practical wisdom (the other forms being (1) the faculty of managing a household, (2) the legislative faculty, (3) statesmanship [in the narrower sense], which is subdivided into (a) the deliberative, (b) the judicial faculty).
Knowing one’s own good, then, would seem to be a kind of knowledge (though it admits of great variety), and, according to the general opinion, he who knows and attends to his own affairs is prudent, while statesmen are busybodies, as Euripides says—
“What? was I wise, who might without a care
Have lived a unit in the multitude
Like any other unit? . . .
For those who would excel and do great things—”
For men generally seek their own good, and fancy that is what they should do; and from this opinion comes the notion that these men are prudent.
And yet, perhaps, it is not possible for a man to manage his own affairs well without managing a household and taking part in the management of a state.
Moreover, how a man is to manage his own affairs is not plain and requires consideration. And this is attested by the fact that a young man may become proficient in geometry or mathematics and wise in these matters, but cannot possibly, it is thought, become prudent. The reason of this is that prudence deals with particular facts, with which experience alone can familiarize us; but a young man must be inexperienced, for experience is the fruit of years.
Why again, we may ask, can a lad be a mathematician but not wise, nor proficient in the knowledge of nature? And the answer surely is that mathematics is an abstract science, while the principles of wisdom and of natural science are only to be derived from a large experience; and that thus, though a young man may repeat propositions of the latter kind, he does not really believe them, while he can easily apprehend the meaning of mathematical terms.
Error in deliberation, again, may lie either in the universal or in the particular judgment; for instance, you may be wrong in judging that all water that weighs heavy is unwholesome, or in judging that this water weighs heavy. But prudence [in spite of its universal judgments] plainly is not science; for, as we said, it deals with the ultimate or particular fact [the last link in the chain], for anything that can be done must be of this nature.
And thus it is in a manner opposed to the intuitive reason also: the intuitive reason deals with primary principles which cannot be demonstrated, while prudence deals with ultimate [particular] facts which cannot be scientifically proved, but are perceived by sense—not one of the special senses, but a sense analogous to that by which we perceive in mathematics that this ultimate [particular] figure is a triangle; for here too our reasoning must come to a stand. But this faculty [by which we apprehend particular facts in the domain of practice] should, after all, be called sense rather than prudence; for prudence cannot be defined thus.