Book VI, Chapter V

As for Practical Wisdom, we shall ascertain its nature by examining to what kind of persons we in common language ascribe it.

It is thought then to be the property of the Practically Wise man to be able to deliberate well respecting what is good and expedient for himself, not in any definite line, as what is conducive to health or strength, but what to living well. A proof of this is that we call men Wise in this or that, when they calculate well with a view to some good end in a case where there is no definite rule. And so, in a general way of speaking, the man who is good at deliberation will be Practically Wise. Now no man deliberates respecting things which cannot be otherwise than they are, nor such as lie not within the range of his own action: and so, since Knowledge requires strict demonstrative reasoning, of which Contingent matter does not admit (I say Contingent matter, because all matters of deliberation must be Contingent and deliberation cannot take place with respect to things which are Necessarily), Practical Wisdom cannot be Knowledge nor Art; nor the former, because what falls under the province of Doing must be Contingent; not the latter, because Doing and Making are different in kind.

It remains then that it must be “a state of mind true, conjoined with Reason, and apt to Do, having for its object those things which are good or bad for Man:” because of Making something beyond itself is always the object, but cannot be of Doing because the very well-doing is in itself an End.

For this reason we think Pericles and men of that stamp to be Practically Wise, because they can see what is good for themselves and for men in general, and we also think those to be such who are skilled in domestic management or civil government. In fact, this is the reason why we call the habit of perfected self-mastery by the name which in Greek it bears, etymologically signifying “that which preserves the Practical Wisdom:” for what it does preserve is the Notion I have mentioned, i.e. of one’s own true interest.

For it is not every kind of Notion which the pleasant and the painful corrupt and pervert, as, for instance, that “the three angles of every rectilineal triangle are equal to two right angles,” but only those bearing on moral action.

For the Principles of the matters of moral action are the final cause of them: now to the man who has been corrupted by reason of pleasure or pain the Principle immediately becomes obscured, nor does he see that it is his duty to choose and act in each instance with a view to this final cause and by reason of it: for viciousness has a tendency to destroy the moral Principle: and so Practical Wisdom must be “a state conjoined with reason, true, having human good for its object, and apt to do.”

Then again Art admits of degrees of excellence, but Practical Wisdom does not: and in Art he who goes wrong purposely is preferable to him who does so unwittingly, but not so in respect of Practical Wisdom or the other Virtues. It plainly is then an Excellence of a certain kind, and not an Art.

Now as there are two parts of the Soul which have Reason, it must be the Excellence of the Opinionative [which we called before calculative or deliberative], because both Opinion and Practical Wisdom are exercised upon Contingent matter. And further, it is not simply a state conjoined with Reason, as is proved by the fact that such a state may be forgotten and so lost while Practical Wisdom cannot.

BOOK VI, Chapter VI

Now Knowledge is a conception concerning universals and Necessary matter, and there are of course certain First Principles in all trains of demonstrative reasoning (that is of all Knowledge because this is connected with reasoning): that faculty, then, which takes in the first principles of that which comes under the range of Knowledge, cannot be either Knowledge, or Art, or Practical Wisdom: not Knowledge, because what is the object of Knowledge must be derived from demonstrative reasoning; not either of the other two, because they are exercised upon Contingent matter only. Nor can it be Science which takes in these, because the Scientific Man must in some cases depend on demonstrative Reasoning.

It comes then to this: since the faculties whereby we always attain truth and are never deceived when dealing with matter Necessary or even Contingent are Knowledge, Practical Wisdom, Science, and Intuition, and the faculty which takes in First Principles cannot be any of the three first; the last, namely Intuition, must be it which performs this function.