science of contraries, or that there is not the same. But it is not proper to question the conclusion after the manner of a proposition, since some things are not to be questioned, but to be employed as if acknowledged.
Chapter 16
From what places then questions are, and how we must make them in contentious exercises, has been shown; but concerning reply, and how it is proper to solve, and what, and for what use such arguments are profitable, must be stated in the next place.
They are useful then to philosophy for two causes; first, indeed, as being for the most part from diction, they enable us to know in a better manner, in how many ways each thing is predicated, and what kind happen similarly, and what differently, both in things and in names. Secondly, (they contribute) to inquiries by oneself, for he who is easily deceived by a paralogism by another, and does not perceive this, may also himself frequently experience the same thing from himself. Thirdly, in the remaining place, (they tend) still more to fame from appearing to be exercised about all things, and not to be unskilful in any thing; for that he who engages in disputation should blame the arguments (of another), without being able to distinguish any thing about their badness, produces a suspicion of apparent indignation, not on account of the truth, but on account of unskilfulness.
How therefore respondents should oppose such arguments is evident, since we have before rightly
