Aristotle on practical wisdom, part 3
[NB: This is the third in a series of posts about Book VI of the Nicomachean Ethics. I explain the project in Part 1.]
I claimed in Part 2 that EN VI is structured around a search for the kind of reason that explains how we can go about correctly choosing the mean, that is, making the right ethical choice. As Aristotle points out in the first half of VI.2, reasoning of this sort belongs to the more general category of reasoning about contingent things, which is the province of the faculty for calculation, to logistikon (1139a3-15).
Not all calculation is about ethical matters, of course, since calculation is also present in crafts such as medicine. It’s perhaps worth noting here that I don’t think Aristotle is committed to the thought that all ethical reasoning is calculative, either. We might think that the theoretical enterprise of the ethical works themselves is also a form of reasoning, namely, inquiry. And ethical inquiry is not calculative since it is not directed in the first instance toward what is contingent, that is, the sphere of particular and determinate actions, although it certainly seeks to shape our calculative reasoning.
Aristotle is in quite direct conversation with Plato throughout this passage, even deploying the familiar argument from Republic V that cognitive states are distinguished according to the ontological status of their objects, in order to distinguish the faculty for scientific knowledge (to epistêmonikon), whose objects are necessary, from that for calculation (1139a6-11). There’s another interesting connection to Plato in Aristotle’s use of logistikon to denote the sphere to which the reasoning that leads to correct choice belongs.
I’m thinking of the opening pages of the Statesman where Plato has the Eleatic Stranger divide up the various forms of knowledge. The top-level division is between cognitive and practical knowledge (epistêmê gnôstikê and praktikê), but the former is further subdivided into discriminatory (kritikon) and directive (epistatikon) varieties (258b-260b). The knowledge needed to rule, the Stranger argues, falls into the last category, the cognitive but directive variety. In the second subdivision, this knowledge is contrasted with none other than calculation or reckoning, logistikê, which is concerned only with forming judgments (gnôsis) and so falls into the merely discriminatory.
One of the striking things about this contrast is that directive knowledge also involves making judgments, but differs in putting them to further use by issuing orders (259e-260a). Both discriminatory and directive knowledge involve judgments – that seems to be what makes them cognitive (gnôstikê), which we might also translate ‘judgmental’ – but then discriminatory knowledge looks like the pure case and directive knowledge ends up seeming a little strange. (Indeed, when the first division is introduced, the Stranger’s presumably paradigmatic example of cognitive knowledge is arithmetic, which may signify the same thing as calculation – 258d.) Why should the further use of a judgment affect the nature of the faculty or species of knowledge that issues it? Why not think two separate faculties are involved?
When Aristotle adopts the term calculative and then applies it to the other side of this contrast, he is, I think, partly drawing on an analogy to mathematical judgment in order to bolster the cognitive credentials of the kind of ethical reasoning in which he is interested, perhaps because of questions such as these about the Platonic view. Correspondingly, it is no surprise that his favored mathematical metaphor for deliberation is geometric construction. For this type of mathematical reasoning involves particulars in a way that the arithmetic reasoning that Plato tends to speak of does not obviously do, but retains its evidently inferential quality.
What I think is important to see here is that the underlying question that both Plato’s Stranger and Aristotle are addressing is the same – how do reasoning about what’s best to do and actually getting those things done relate to one another? I take it that Aristotle’s full answer takes up most if not all of Books VI and VII of the Ethics, and he takes on the task headlong in the tricky second part of VI.2, which I hope to write about next.
 I write ‘contingent’ and ‘necessary’ as short-hand for ‘what has starting points that admit of being otherwise’ and ‘what has starting points that do not admit of being otherwise’. I’m not sure why Aristotle draws the distinction this way. Perhaps he is merely being careful to distinguish statements, which have the relevant kind of modal properties, and things that those statements are about, which do not.
 Leaving aside the most obvious point of comparison, that logistikon signifies the whole of the thinking part of the soul in the Republic (introduced explicitly at IV.439d).
 Most notably at EN III.3, 1112b20-24. A certain conclusion in geometry, however, is mentioned as a paradigmatic case of something we do not deliberate about at III.3, 1112a21-23.