Aristotle, Nicomachean Ethics
H. Rackham, Ed.

The class of things that admit of variation includes both things made and actions done. [2] But making is different from doing （a distinction we may accept from extraneous discourses¹）. Hence the rational quality concerned with doing is different from the rational quality concerned with making; nor is one of them a part of the other, for doing is not a form of making, nor making a form of doing. [3] Now architectural skill, for instance, is an art, and it is also a rational quality concerned with making; nor is there any art which is not a rational quality concerned with making, nor any such quality which is not an art. It follows that an art is the same thing as a rational quality, concerned with making, that reasons truly. [4] All Art deals with bringing some thing into existence; and to pursue an art means to study how to bring into existence a thing which may either exist or not, and the efficient cause of which lies in the maker and not in the thing made; for Art does not deal with things that exist or come into existence of necessity, or according to nature, since these have their efficient cause in themselves. [5] But as doing and making are distinct, it follows that Art, being concerned with making, is not concerned with doing. And in a sense Art deals with the same objects as chance, as Agathon says: “ Chance is beloved of Art, and Art of Chance.

” [6]

Art, therefore, as has been said, is a rational quality, concerned with making, that reasons truly. Its opposite, Lack of Art, is a rational quality, concerned with making, that reasons falsely. Both deal with that which admits of variation.5.

We may arrive at a definition of Prudence by considering who are the persons whom we call prudent. Now it is held to be the mark of a prudent man to be able to deliberate well about what is good and advantageous for himself, not in some one department, for instance what is good for his health or strength, but what is advantageous as a means to the good life in general. [2] This is proved by the fact that we also speak of people as prudent or wise in some particular thing, when they calculate well with a view to attaining some particular end of value （other than those ends which are the object of an art）; so that the prudent man in general will be the man who is good at deliberating in general. [3]

But no one deliberates about things that cannot vary, nor about things not within his power to do. Hence inasmuch as scientific knowledge involves demonstration, whereas things whose fundamental principles are variable are not capable of demonstration, because everything about them is variable,