[3] After R. Meir died, and despite R. Judah ben Ilai's reluctance to teach R. Meir's students (who were considered "vexatious" students), Symmachus joined R. Judah ben Ilai's class and debated halakhic matters with him.
[3] Symmachus' brilliance was described as follows: R. Abbahu stated in the name of R. Johanan: R. Meir had a disciple of the name of Symmachus who said, on every rule concerning a ritual uncleanness, there are forty-eight reasons in support of its uncleanness, and on every rule concerning a ritual cleanness, forty-eight reasons in support of its cleanness.
The Sages, however, disagreed with him: "It is a fundamental principle in law: One who wishes to extract money from another person, the burden of proof falls on him [the claimant]" (המוציא מחברו עליו הראיה).
[5]Later opinions differ on which situations Symmachus intended for his rule to apply.
[7] In Epiphanius' treatise On Weights and Measures, a certain Symmachus is said to have converted to Judaism from the Samaritan religion at the time of the Roman Emperor Marcus Aurelius who is also called Verus.