Montesquieu

The laws that send a man to his death on the depo­si­tion of a sin­gle wit­ness are fatal to free­dom. Reason requi­res two, because a wit­ness who asserts and an accu­sed who denies make a tie, and there must be a third to decide it.

The Greeks1 and the Romans2 requi­red an addi­tio­nal voice in order to condemn. Our French laws require two. The Greeks clai­med that their prac­tice had been esta­bli­shed by the gods,3 but it is ours.

See Aristides, Oratio in Minervam [’Oration against Minerva’].

Dionysius of Halicarnassus, on the judgment of Coriolanus (book VII).

Minervæ calculus [’Minerva’s vote’].