In Benjamin Aryeh Hakohen Weiss's "Even Yekarah” (Choshen Mishpat, sec. 20) it refers to an ancient gentile text which specifies that when the state government has no minority/opposition members, it should be dissolved and reappointed because of the importance of opposition. Can anyone help me identify the ancient text to which he refers?
Here is a translation of the relevant section:
34 voting to convict would result in a conviction, a decision by all 71 to convict would result in an acquittal!
I answered that he was quite right [about the talmudic ruling]. According to what was said in a book by one of the ancient gentile sages, in the part discussing state government, any assembly that does not have an opposition, a minority opposed to the majority, does not fulfill its calling, and should be dissolved and new assemblymen appointed. Because in the nature of things, every man is capable of error—and not only individuals; in any given matter, large groups can err as well. And so there is a need for sifting the truth from conflicting arguments, as the holder of each respective opinion strives to establish his view through arguments and analogies and thus vanquish opposing views. And if, after the airing of differing views, the majority chooses to accept one of them, it is clear that that is the true one. But this is not the case if only one view is presented without opposing evidence and arguments, [for] that does not create the debate necessary for determining true views. After all, all their intellects could have been captivated by error, thus being mistaken in judgment, and so the assembled group has not fulfilled its required goal.
Thus the words of our sages are quite just. For the Sanhedrin was a gathering of sages with the responsibility to adjudicate matters of life and death: whether to afflict or to show mercy. Hence, if with regard to a given matter, some moved to convict and others to acquit, there was then a genuine debate necessary to arrive at the truth. Then, if after [the debate], the majority of sages gathered there agreed to convict the defendant standing before them, their judgment is free of doubt, and the defendant is definitely guilty, and their decision is true and their judgment just. But if there were only judges voting to convict, with nobody to contest their view, no one working to demonstrate the truth of alternative reasoning, it is only natural that they may all have erred, and thus that they will spill an innocent's blood. And so their words are just, [namely] that if all of them vote to convict, the defendant shall go free and not be condemned by the judgment of this panel, which may simply be seeing things incorrectly.
And my wise interlocutor saw my point [about our sages] and proceeded to sing their praises.