Epictetus, Golden Sayings 113

Furthermore, the true Cynic must know that he is sent as a Messenger from God to Men, to show unto them that as touching good and evil they are in error; looking for these where they are not to be found, nor ever bethinking themselves where they are. 

And like Diogenes, when brought before Philip after the battle of Chaeronea, the Cynic must remember that he is a Spy. For a Spy he really is—to bring back word what things are on Man's side, and what against him. 

And when he had diligently observed all, he must come back with a true report, not terrified into announcing them to be foes that are no foes, nor otherwise perturbed or confounded by the things of sense.