Without naming any names, the conservative justice also said during an event with students at Georgetown University that recent attacks against Supreme Court justices have gone too far.

“The notion that rule of law governs is the basic proposition,” Roberts said, according to Politico. “We need to stop and reflect every now and then how rare that is, certainly rare throughout history, and rare in the world today.”

In response to a student’s question, he also said criticism of the Supreme Court is a good thing—“so long as it is not trashing the justices,”