In ancient Greece, a philosopher used to inculcate ‘art of argumentation’. He was such an accomplished master of his profession that he offered pupils to pay him fees only if they win their first argument with anyone; more than that he started offering double the amount of his fees as a promotion program to anyone who lost his first argument with anyone after having spent enough time under his tutelage. The amazing thing was: he never had to pay back to any disciple and he always got his fees because of his impeccable teaching.
A very curious looking disciple joined him one day. He was very quiet and refined in appearance. He was very taciturn and rarely asked any questions. He mastered the art of argumentation at a great rate. When the day of examination came, to the astonishment of entire country- disciple challenged the Guru, instead of challenging anyone else. Guru could not reject the challenge, because, in that case his reputation would have got spoiled.
The disciple alleged that he did not owe any money to the Guru. The Guru had an unforeseen dilemma before him. If he would have refuted the assertion and won the argument he would have been compelled to part with the fame that years upon years of Sophistry had earned him and had he lost the argument he would have paid twice the amount he was going to take from his disciple as fees.
Guru surrendered after pondering for a while and disciple went away with money as well as Sophistry in his baggage.