I turn to Aristotle's discussion of practical wisdom (phronēsis). This more than most is rough terrain for commentators, being densely thicketed with controversy. Some of the difficulties spring from the obscurity of Aristotle's exposition, while some flourish through our own confusing preconceptions. Since one cannot thread a way through the layers of all this in footnotes, exegetical problems and attendent conceptual diagnoses will occupy much of this chapter.
Aristotle defines practical wisdom as the virtue by which one deliberates well: i.e., reasons well in a practical way (1140 24 ff.). What is practical reason? It has two aspects: the rational choice (prohairesis) on which a person acts, and the process of deliberation or reflection by which a rational choice is formed. To Aristotle these are conceptually inseparable: just as the aim of deliberation is to reach a reasoned choice, so rational choice is reached only through deliberation. The first connection goes without saying, but the second depends on what one means by 'deliberation'. In one sense the statement is plainly false. It is easy to think of deliberation and rational choice as process and product; and surely we can sometimes have what a process normally produces without the process? We have already glanced at this question in Chapter 2, Section VI, and we shall return to it later here. Meanwhile I focus on the product. This has a dual structure: a rational choice, Aristotle says at EE 1227 b 36, is of X for the sake of Y. It cannot be characterised without reference to both. A choice of X for the sake of Z and one of X for the sake of Y are as different (though in a different way) as the choice of X for the sake of Y and of W for the sake of Y. This complexity implies two complementary ways of evaluating rational choice. Y may or may not be an appropriate end, and X may or may not be an appropriate means.
This structure has implications for the sense in which an agent explains his choice of X by stating that Y is the end. For, of course, 'It is for Y' gives his reason for choosing X, and for doing it if he acts on the choice. But in indicating Y, the agent does not refer to a factor extraneous to his choosing of X: a factor related to