(adapted)

The Scene: "Corax and his pupil Tisias were reputedly the first Sophists. Like many young men with an appetite for worldly success, Tisias sought training from Corax in the hope of being able to sue his way to wealth and influence. Wishing to make sure he was not duped by his teacher, Tisias contracted to pay Corax only after he had actually won a law suit. On this condition his training commenced and soon enough was over. But Tisias became complacent. Years went by and Tisias brought no suits against anyone. Corax had been willing to wait to be paid, but not forever, so he brought a suit against Tisias to recover his fee" -- Britannica.com

Tisias: Your Honors, I stand before you today in humility of spirit and purity of motive. I ask only that you listen patiently and judge rightly in issuing your verdict.

Your Honors, I charge Corax for failing to teach me well the art of Rhetoric. The proof of this charge is here before us today. For if I should lose my case, it will surely prove that I was not taught Rhetoric very well. And this being the case I should NOT have to pay the tuition. For no one should have to pay for services that weren't rendered according to what was promised.

On the other hand, if I win the case, it shows that I had enough sense and talent to figure out the art of Rhetoric out on my own, despite the negligence of my instructor. But even this is not necessary to my case. For a ruling against Corax, is a ruling for me. And a ruling for me means I do not have to pay tuition. In either case, then, I should NOT have to pay tuition.  

Corax:  Your Honors, I, too, stand humbly before you. I, too, recognize, in years far more experienced than that of my adversary, your outstanding record of prudent and just decision making on behalf of those whose cause is just. We are indeed fortunate to gain a hearing before you. This, then, is my case.

I have given Tisias the very best education in rhetoric of which I am capable, on the condition that he would at some point in his career pay my tuition. This he has not done. Now, if you rule against me -- that is if Tisias does in fact win his case -- it serves to show that I taught him Rhetoric well, in which case he should be required to pay my tuition. If, however, Tisias does not win his case, that would show him to be a poor, or rather bad, student. (We already know he is poor.) Those who are wise well know that a teacher is not to be faulted if, in discharging his services well and faithfully, the student is simply too stupid or too lazy (or too both) to take advantage of those services, expertly rendered.

But even this is unnecessary to my case. For a ruling against Tisias is a ruling in favor of me. Such a ruling would, of course, mean that Tisias must pay my tuition. In either case, then, my tuition should be paid.