Against Alcibiades 2 (7-8)

And it is monstrous also, in my opinion, gentlemen, that whereas it is not in their power to take a man at their own pleasure from the cavalrymen who have passed scrutiny, and enrol him in the infantry, it should be in their power to pass a man at their pleasure from the infantry into the cavalry without scrutiny.

Now, gentlemen, if they were entitled so to act, and allowed none of the many others who so desired to serve in the cavalry, you would not be justified in obliging them; but if they admit that they were not entitled to rank him as they have done, you should reflect that you have sworn to decide according to justice, and not to vote in compliance with these men; and so you ought not to have more regard for any of these suitors than for yourselves and your oaths.