Book 6
4
Now we have divided the Virtues of the Soul into two groups, the Virtues of the Character and the Virtues of the Intellect. The former, the Moral Virtues, we have already discussed. Our account of the latter must be prefaced by some remarks about psychology.
5
It has been said before1.13.9. that the soul has two parts, one rational and the other irrational. Let us now similarly divide the rational part, and let it be assumed that there are two rational faculties, one whereby we contemplate those things whose first principles are invariable, and one whereby we contemplate those things which admit of variation: since, on the assumption that knowledge is based on a likeness or affinity of some sort between subject and object, the parts of the soul adapted to the cognition of objects that are of different kinds must themselves differ in kind.
6
These two rational faculties may be designated the Scientific Faculty and the Calculative Faculty respectively; since calculation is the same as deliberation, and deliberation is never exercised about things that are invariable, so that the Calculative Faculty is a separate part of the rational half of the soul.
7
We have therefore to ascertain what disposition of each of these faculties is the best, for that will be the special virtue of each.
7
But the virtue of a faculty is related to the special function which that faculty performs.
1
Now there are three elements in the soul which control action and the attainment of truth: namely, Sensation, Intellect,νοῦς here bears its usual philosophic sense of the intellect, or rational part of the soul, as a whole, whose function is διάνοια, thought in general. In chap. 6 it is given a special and restricted meaning, and this in chap. 9 is related to the popular use of the word to denote good sense or practical intelligence. and Desire.
