[2[ For it is hard to speak properly upon a subject where it is even difficult to convince your hearers that you are speaking the truth. On the one hand, the friend who is familiar with every fact of the story may think that some point has not been set forth with that fullness which he wishes and knows it to deserve; on the other, he who is a stranger to the matter may be led by envy to suspect exaggeration if he hears anything above his own nature.