Just as it is possible to interchange terms which are equivalent to one another, so and in just as many ways it is allowable to vary in argument the types of disputative argument and enthymeme. Take for instance this kind of argument: 'If you borrowed and did not repay, you owe me the money. You did not borrow without repaying; therefore you do not owe me the money.' And the philosopher above all others is the proper person to handle such arguments with skill. For if enthymeme is imperfect syllogism, plainly he who is trained in perfect syllogism would be equally capable in dealing with imperfect.
Why then, you ask, do we not train ourselves and one another in this style of argument? Because even now, though we do not devote our-
selves to training in these matters and though we are not drawn away, so far as I have any influence, from cultivating character, nevertheless we make no advance towards goodness. What should we have to expect then, if we should add this business to our other employments? And there is more—not only should we have less leisure for more necessary things, but we should give uncommon occasion for conceit and vanity. For the faculty of disputative and plausible reasoning is a powerful one, especially if it should be developed by training and gain further dignity from mastery of language. For indeed generally every faculty is dangerous when it comes into the hands of those who are without education and without real force, for it tends to exalt and puff them up. For how would it be possible to persuade the young man who excels in these arguments that he ought not to become dependent upon them, but to make them depend upon him? Instead of this he tramples under foot all we say to him and walks among us in a high state of elation, so puffed up that he cannot bear that any one should remind him how far he has fallen short and into what errors he has lapsed.
'What do you mean? Was not Plato a philosopher?'
I reply, Was not Hippocrates a physician? But you see how eloquent Hippocrates was. Was Hippocrates so eloquent by virtue of being a physician? Why then do you mix qualities, which are casually united in the same persons? Suppose Plato was handsome and strong; ought I also to set to and strive to become handsome or strong, as though this were necessary for philosophy, just because one philosopher was handsome as well? Will you not have the discernment to see what makes men philosophers and what qualities are accidental in them? Suppose now I were a philosopher, ought you to become lame?
You ask me, do I then count these faculties as of no effect?
Heaven forbid! no more than I ignore the faculty of vision. Nevertheless if you ask me what is the true good of man, I can only say to you that it lies in a certain disposition of the will.