Consequently, though a number of orators, who have studied the same rules, will use similar kinds of arguments, one will discover a greater number of arguments to suit his case than another. Let us take as an example a controversial theme involving problems that have little in common with other cases.

When Alexander destroyed Thebes, he found documents showing that the Thebans had lent a hundred talents to the Thessalians. These documents he presented to the Thessalians as a reward for the assistance they had given him in the campaign. Subsequently the Thebans, after the restoration of their city by Cassander, demanded that the Thessalians should repay the money. The case is tried before the Amphictyonic council. It is admitted that the Thebans lent the money and were not repaid.

The whole dispute turns on the allegation that Alexander had excused the Thessalians from payment of the debt. It is also admitted that the Thessalians had received no money from Alexander. The question is therefore whether his gift is equivalent to his having given them money.

What use will formal topics of argument be in such a case, unless I first convince myself that the gift of Alexander made no difference, that he had not the power to make it, and that he did not make it? The opening of the Thebans' plea presents no difficulty and is likely to win the approval of the judges, since they are seeking to recover by right what was taken from them by force. But out of this point arises a violent controversy as to the right of war, since the Thessalians urge that kingdoms and peoples and the frontiers of nations and cities depend upon these rights.