M. Tullius Cicero Pro A. Cluentio 53

[53] When I urged at some length the argument, that plot might have been laid against Scamander by Diogenes, and that it might have been arranged between them on some other account that Diogenes should bring him medicine, not poison that this might happen to any one; he asked why he came into such a place as that, into so secret a place, why he came by himself, why he came with a sum of money sealed up. And lastly, at this point, our cause was weighed down by witnesses, most honourable men. Marcus Bebrius said that Diogenes had been bought by his advice, and that he was present when Scamander was seized with the poison and the money in his possession. Publius Quintilius Varus a man of the most scrupulous honour, and of the greatest authority, said that Cleophantus had conversed with him about the plots which were being laid against Habitus, and about the tampering with Diogenes, while the matter was fresh.