Against Alcibiades 1 (12-13)

And besides, gentlemen, I conceive that your judgement is given, not merely with a view to the offenders, but also for the reformation of all other insubordinate persons. Now, if you punish men who are unknown, not one among the rest will be improved; for nobody will know the sentences that you have passed: but if you inflict the penalty on the most conspicuous offenders, everyone will be apprised, and so the citizens, with this example before them, will be improved.

Again, if you condemn this man, not only will the people of our city know, but our allies also will take notice and our enemies will be informed; and they will hold our city in much higher regard if they see that you are especially indignant at this kind of offence, and that those who are insubordinate in war obtain no pardon.