Nicomachean Ethics VI.8

This is an important chapter. Today is an inauspicious day for it because of the political murder of the early afternoon, but the wisdom it speaks of is eternal.

Political wisdom and practical wisdom are the same state of mind, but their essence is not the same. Of the wisdom concerned with the city, the practical wisdom which plays a controlling part is legislative wisdom, while that which is related to this as particulars to their universal is known by the general name 'political wisdom'; this has to do with action and deliberation, for a decree is a thing to be carried out in the form of an individual act. This is why the exponents of this art are alone said to 'take part in politics'; for these alone 'do things' as manual labourers 'do things'.

So too we don't assign to legislators but to the bureaucrats who execute and define policy the idea of action. In our system, legislators are mostly fundraisers who delegate authority to bureaucrats. It's the bureaucrats who decide; and the police who execute the decisions not of the legislature, but of the bureaucracy.

Practical wisdom also is identified especially with that form of it which is concerned with a man himself-with the individual; and this is known by the general name 'practical wisdom'; of the other kinds one is called household management, another legislation, the third politics, and of the latter one part is called deliberative and the other judicial.

This is Aristotle carefully avoiding the fallacy of composition. It is commonly and wrongly assumed that knowing how to order one level of human activity -- being a good businessman, for example -- ought to transfer to governance, family leadership, etc. It does not. Many a good businessman is a terrible husband; many a politician couldn't run a business to save their lives.

Now knowing what is good for oneself will be one kind of knowledge, but it is very different from the other kinds; and the man who knows and concerns himself with his own interests is thought to have practical wisdom, while politicians are thought to be busybodies; hence the word of Euripides, [Grim: Shocklingly to English speakers, that is pronounced euro-PEE-dees, as Socrates is soh-KRAT-ees.]

But how could I be wise, who might at ease,

Numbered among the army's multitude,

Have had an equal share?

For those who aim too high and do too much. Those who think thus seek their own good, and consider that one ought to do so. From this opinion, then, has come the view that such men have practical wisdom; yet perhaps one's own good cannot exist without household management, nor without a form of government. Further, how one should order one's own affairs is not clear and needs inquiry.

I hope Aristotle is wrong about the latter part of that point.

What has been said is confirmed by the fact that while young men become geometricians and mathematicians and wise in matters like these, it is thought that a young man of practical wisdom cannot be found.

Depending on what you mean by "young," of course; many a sergeant is wise at 25. But Aristotle might have meant 15. 

The cause is that such wisdom is concerned not only with universals but with particulars, which become familiar from experience, but a young man has no experience, for it is length of time that gives experience; indeed one might ask this question too, why a boy may become a mathematician, but not a philosopher or a physicist.

This is the difference between philosophy and history; philosophy seeks the universals from the particulars, but history focuses on getting the particulars exactly correct. Adding philosophy, as the Marxists do in their histories, causes you to get the history wrong. It makes things seem plausible that aren't true. 

It is because the objects of mathematics exist by abstraction, while the first principles of these other subjects come from experience, and because young men have no conviction about the latter but merely use the proper language, while the essence of mathematical objects is plain enough to them?

Also true of AI, by the way. That might be important to remember: they are plausibility machines that just know how to use language the right way. There's no reason to think that anything they tell you is true.

Further, error in deliberation may be either about the universal or about the particular; we may fail to know either that all water that weighs heavy is bad, or that this particular water weighs heavy.

Unless you want to make nuclear weapons; then heavy water is good. 

That practical wisdom is not scientific knowledge is evident; for it is, as has been said, concerned with the ultimate particular fact, since the thing to be done is of this nature. It [i.e practical wisdsom] is opposed, then, to intuitive reason; for intuitive reason is of the limiting premisses, for which no reason can be given, while practical wisdom is concerned with the ultimate particular, which is the object not of scientific knowledge but of perception-not the perception of qualities peculiar to one sense but a perception akin to that by which we perceive that the particular figure before us is a triangle; for in that direction as well as in that of the major premiss there will be a limit. But this is rather perception than practical wisdom, though it is another kind of perception than that of the qualities peculiar to each sense.

That's a tremendously important insight. Let's discuss it in the comments if any of you wish.