Aristotle, Topics. Book I, Chapter 2
by William C. Michael
Translation by Thomas Taylor
To what has been said in chapter 1, it will be consequent to show in what the ability of this treatise consists, and how far its utility is extended. It is useful, therefore, to three things: to exercise, to common conversation, and to philosophic sciences.
That it is useful indeed to exercise, is from these things evident; for possessing this method, we may be easily able to argue on every proposed subject.
But it is useful to common conversation; because, when the opinions of the multitude are enumerated, we may converse with them not from foreign, but appropriate dogmas, confuting whatever does not appear to us to have been well said.
And it is useful to philosophic sciences, because when we are able to doubt on both sides of a question, we can easily in everything perceive the true and the false.
Again, it is also useful to the first principles of every science. For it is impossible to say anything about these, from the appropriate principles of a proposed science, because they are the first principles of all sciences. But it is necessary to discuss these through probabilities in particulars. This, however, is the peculiarity of, or is especially appropriate to dialectic. For as it is of an exploring nature, it is a path to the principles of all methods.