"Phronesis has no authority over sophia or the better part of our soul" (1145a8-9) but sophia "will study none of the things that make a man happy" (1143b119).

With regard to the whether the intellectual virtues are "natural" (given by nature), Aristotle does say that, except for theoretical wisdom (sophia), the intellectual virtues are "natural endowments," and "we do think that men have good sense (gnome), understanding (synesis), and intelligence (nous) by nature" (1143b8-9). (Why does he exempt sophia?) He also immediately adds that the intellectual virtues are "learned" by maturing through various "stages of life," but be still reminds us that "(human) nature is the cause." So the best conclusion we can draw here is that the intellectual virtues are a combination of nature and learning, while the moral virtues, except for the phronesis that shapes them, are all learned. Aristotle concludes this particular discussion on a rather profound note: we should consider the practical wisdom of our elders as on par with demonstrated truths.

At the end of Book Six Aristotle makes a distinction between "natural" virtue and virtue "in the full sense" (1144b3). Here, contrary to what I want to say above, the focus is on moral virtues that we are born with and the mature virtues that we must use phronesis to obtain. Furthermore, humans are born with an incomplete set of natural virtues, but the truly good person develops a complete and comprehensive ensemble of the virtues such that all the mature virtues are unified. As Aristotle states: "As soon as he possesses the single virtue of practical wisdom, he will also possess all the rest" (1145a1-2).

Intelligence (nous). Nous is that human faculty that apprehends fundamental principles such as the laws of thinking and other fundamental truths. Nous apprehends these truths directly and without demonstration or inference, which is the job of "theoretical wisdom" (sophia). The importance that Aristotle gives to nous is seen in this definition of human nature: "Intelligence (nous), above all else, is man" (1178a8). Nous is also used less frequently to refer to practical reasoning, and in one passage he states that we love nous in this practical sense more than any other human faculty (1169a3). Aristotle follows Plato in using the metaphor of nous as the "eye of the soul" (1143b13; 1144a30), the mind's eye or the "third eye" that "looks" inward at rational things rather than outward towards sensible objects.

Theoretical Reason (sophia). Sophia is a combination of knowledge of fundamental principles (nous) and knowledge of what follows from those principles (theoria). Sophia is science "in its consummation . . . the science of the things that are valued most highly" (1141a20-1). True to the spirit of Book Ten Aristotle reminds us that practical goods are not the most highly valued, because there are higher beings in the cosmos with whom we share reason, so the goods of theoretical reason are the highest values. Aristotle observes that practical reasoning could even be discerned in some things animals do, but theoretical reasoning is unique to humans and the gods. Right at the end of Book Six we read that the moral virtues are only a stage on life's way that make "the provisions to secure it" (viz., sophia).

Aristotle makes a puzzling observation about the pre-Socratic philosophers Anaxagoras and Thales, whose sophia consists in "extraordinary, wonderful, difficult, and superhuman things," but he also admits that these men did "not know what is advantageous" and that "their knowledge [was] useless because the good they are seeking is not human" (1141b8-9). Even more curious is Aristotle statement that the study sophia will not "make a man happy" (1143b19), which seems to directly contradict Book Ten, unless here Aristotle is making a strict distinction, something he does not elsewhere, between eudaimonia and makarios. This appears to be a slip on Aristotle's part, because very soon we read that sophia does produce eudaimonia after all (1144a3).

Practical Reason (phronesis). Phronesis differs from "science" (theoria) in that the objects of the latter do not change, whereas phronesis deliberates about things that can be other than they are. Phronesis differs from "art" (techne) because it deals with actions rather than products. ("For production has an end other than itself, but action does not: good action is itself an end" [1140b6-7].)

Phronesis unifies reason and desire: it is orexis dianoetike or orektikos nous. It is a "reasoned and true state of capacity to act with regard to human goods" (1140b20-25). But it is does not pick out specific moral goods (these are developed by emulation with the aid of phronesis) or other means/ends but general goal of the good life itself–"what sorts of things conduce to the good life in general" (1140a25-30). Phronesis produces intelligent goodness not just semblances of goodness. It also very significantly is the key factor in the unity of the virtues. If phronesis gets one virtue right then it will get them all right.

Phronesis gives us the ability to develop virtues that are means "relative to us"; and enables us to determine the right amount, the right means, the right goal, the right time, the right situation, the right person, etc. I would like to call this Aristotle's "contextual pragmatism": "what is suitable is . . . relative to the person, the circumstances, and the object" (1122a25-6). As John Casey state: "It is the ability to ‘see’ what is at stake where the application of rules may not be at all obvious, and to know how to respond. It can go beyond knowing how to act. We can think of the man of practical wisdom as having moral imagination" (Pagan Virtue, p. 147).

Aristotle's distinction between theoretical and practical wisdom represents a decisive break with Plato, who, at least in the Socrates of the early dialogues, equated theoretical knowledge and virtue. In stark contrast Aristotle observes that while young people gain theoretical wisdom by studying geometry and math, "they apparently do not attain practical wisdom. The reason is that practical wisdom is concerned with particulars as well (as with universals), and knowledge of particulars comes from experience" (1142a10ff). Later on Aristotle phrases his point with an odd, but effective locution, fusing the particular with the universal (or a telos, to be more precise): phronesis "is concerned with ultimate particulars, since the actions to be performed are ultimate particulars" (1142a23-5). (Much later Hegelians would call these "concrete universals.") Aristotle adds that there is a nonsensory "perception" of these ultimate particulars but there is no theoria, presumably because it would be relative and particular to each individual. Later on Aristotle will call this nonsensory perception the "eye of with which [we] can see correctly" (1143b13). We have already seen that this is the eye of nous, which apparently has taken on a practical function here.

Aristotle makes two claims about phronesis that appear puzzling. First, he says that there is excellence in art but not in phronesis; and second, "in art a man who makes a mistake voluntarily is preferable to one who makes it involuntarily; but in practical wisdom, as in every virtue or excellence, such a man is less desirable" (1140b22-24). Ostwald solves the first puzzle by explaining that phronesis is itself excellence (arete=virtue), while the products of art may either be good (=excellent) or bad. The same can be said of phronesis that Aristotle says of understanding: "There is no difference between understanding and excellence in understanding" (1143a8-9). As to the second point, the example of an craftperson who deliberately makes a mistake in teaching piece in order to test a student's knowledge is not at all morally represensible as is the person who deliberately disrespects a person in order to teach the importance of respect. Another interesting point about this example is the fact that it is inconceivable that a truly virtuous person could chose to "go against the grain" of the habit of virtue.

Aristotle again appears to disagree with Plato in maintaining that phronesis is not a form of "investigation," which belongs to the sciences. Neither is it a form of "shrewd guessing," which involves no reasoning and goes quickly, while phronesis is a form of reason and usually takes some time. ("Quickness of mind" is just another form of guessing.) Deliberation is not a type of opinion (doxa) either, because the objects of opinions are fixed and opinions that conform to their objects will be lead to knowledge not action. But like knowledge and opinion, moral deliberation will be a form of "correctness" defined as "assessing what is beneficial, i.e., correctness in assessing the goal, the manner, and the time" (1142b27-8). Here is Aristotle's contextual pragmatism again.

Understanding and Good Sense (synesis; gnome). Synesis differs from phronesis in that the former only "passes judgment," while the latter "issues commands," "tells us what we ought to do," and leads to action (1143a5ff.) Understanding is like phronesis in that it does deal with the changeable and the practical. It is the capacity to comprehend what someone has said and it enables us to discern practical problems. For Aristotle understanding and learning from experience are essentially the same. Having "good sense" (gnome) is intimately related to understanding, particularly with regard to the latter's capacity to pass judgment. Even more specific is the "good sense" involved in forgiving, pardoning, and making apologies.