Nicomachean Ethics

​Regarding practical wisdom, we might grasp it in this way, by considering whom we call practically wise. Now, it seems to be characteristic of a practically wise man to be able to deliberate well about what is good and advantageous for himself, not in a particular respect, as for instance what sort of things contribute to health or strength, but what sort of things contribute to the good life as a whole. A sign of this is that we also call people practically wise in some particular respect, when they calculate well towards some valuable end, in matters where there is no art. So that, in general, the man who is capable of deliberating would be practically wise. But no one deliberates about things that cannot be otherwise, nor about things that it is impossible for him to do. So that if scientific knowledge is accompanied by demonstration, and there is no demonstration of things whose starting-points can be otherwise (for all such things can also be otherwise), and it is not possible to deliberate about things that exist of necessity, practical wisdom would be neither scientific knowledge nor art; not scientific knowledge because what is doable can be otherwise, and not art because the genus of action is different from that of making. What remains, then, is that it is a true state joined with reason, capable of action in relation to what is good and bad for human beings. For while making has an end other than itself, action cannot; for good action itself is its end. This is why we think Pericles and men like him to be practically wise, because they can see what is good for themselves and what is good for human beings; and we regard as such those who are skilled in household management and politics. Hence also we call temperance by this name, as preserving practical wisdom. And it preserves this kind of judgment. For pleasure and pain do not destroy or distort every judgment (for example, whether a triangle has two right angles or not), but only those concerned with action. For the starting-points of actions are the ends for which they are performed; but to the man who has been ruined by pleasure or pain, the starting-point is at once not apparent, nor does he see that he ought to choose and perform everything for the sake of this end and because of it; for vice is destructive of the starting-point. So that practical wisdom must be a true state joined with reason, capable of action in relation to human goods. Moreover, while there is an excellence of art, there is no excellence of practical wisdom; and in art he who errs willingly is preferable, but in practical wisdom he is less so, just as in the case of the virtues. It is clear, then, that it is a sort of virtue and not an art. And since there are two parts of the soul that possess reason, it must be the virtue of one of them, namely, of the part that forms opinions; for both opinion and practical wisdom are concerned with what can be otherwise. But yet it is not only a state joined with reason; and a sign of this is that whereas there can be forgetfulness of such a state, there is no forgetfulness of practical wisdom.

​Since scientific knowledge is a judgment about universals and things that exist of necessity, and there are starting-points of what is demonstrable and of all scientific knowledge (for scientific knowledge is joined with reason), of the starting-point of what is scientifically known there can be neither scientific knowledge, nor art, nor practical wisdom; for what is scientifically known is demonstrable, while these other states happen to be concerned with things that can be otherwise. Nor indeed is philosophical wisdom concerned with these starting-points; for it is characteristic of the wise man to have demonstration about some things. If, then, the states by which we possess truth and are never deceived about things that cannot or even can be otherwise are scientific knowledge, practical wisdom, philosophical wisdom, and intuitive reason, and it cannot be any of these three (I mean by the three, practical wisdom, scientific knowledge, and philosophical wisdom), what remains is that intuitive reason is of the starting-points.