A weighty discussion at Yale Law School on the role of religion in public service suddenly turned lighthearted during a recent exchange between U.S. Supreme Court Justice Clarence Thomas and his mentor, former U.S. senator John Danforth.

The Feb. 12 discussion between Thomas and Danforth, both Yale Law School alumni, was led by their onetime professor Guido Calabresi, a senior judge on the U.S. Court of Appeals for the Second Circuit.