Sanhedrin 17B

ומה נחש שממית ומרבה טומאה, טהור; שרץ שאינו ממית ומרבה טומאה, אינו דין שיהא טהור? ולא היא, מידי דהוה אקוץ בעלמא.

If a snake, which kills other creatures whose carcasses are impure and thereby increases impurity in the world, is itself nevertheless pure, as it is not included in the list of impure creeping animals, then concerning a creeping animal that does not kill and does not increase impurity, isn’t it logical that it should be pure? This argument is rejected: But it is not so; the logic of the halakha of a creeping animal is just as it is concerning the halakha with regard to an ordinary thorn, which can injure people or animals and can even kill and thereby increase impurity, but is nevertheless pure. It is therefore apparent that this consideration is not relevant to the halakhot of impurity.

אמר רב יהודה אמר רב: כל עיר שאין בה שנים לדבר ואחד לשמוע, אין מושיבין בה סנהדרי. ובביתר הוו שלשה, וביבנה ארבעה: רבי אליעזר ורבי יהושע ורבי עקיבא, ושמעון התימני דן לפניהם בקרקע.

§ Rav Yehuda says that Rav says: With regard to any city that does not have among its residents two men who are able to speak all 70 languages and one additional man who is able to listen to and understand statements made in all the languages, even if he cannot speak all of them, they do not place a lesser Sanhedrin there. The members of the Sanhedrin do not all need to know all of the languages, but there must be at least this minimum number. And in Beitar there were 3 individuals who were able to speak all 70 languages, and in Yavne there were 4, and they were: R' Eliezer, and R' Yehoshua, and R' Akiva, and Shimon HaTimni, who was not an ordained Sage, and he would therefore deliberate before the other judges while seated on the ground, not among the rows of rabbis.