Washington (CNN) -- Oral arguments at the Supreme Court are often a time for the ever-colorful Justice Antonin Scalia to attract attention with a provocative display of his rhetorical gifts and sense of humor. Both were in display this week in a pair of cases heard in public session.
The first dealt with a U.S. law allowing sex offenders who have served their prison sentences to remain in federal custody under what are called civil commitments.
The amusement started when Solicitor General Elena Kagan, arguing in favor of such laws, mistakenly referred to Scalia as the chief justice.
"Mr. Chief -- excuse me -- Justice Scalia," Kagan said, "I didn't mean to promote you quite so quickly." That drew laughter from the audience of several hundred.
Replied Scalia to Kagan, "I'm sure you didn't," bringing a huge roar.
"Thanks for thinking it was a promotion," quipped the real chief justice, John Roberts, sitting next to Scalia on the nine-justice bench.
Less than an hour later, in an international child custody case, Scalia turned heads by suggesting that federal courts show fidelity to the views of courts from other nations on the issue.
"The purpose of a treaty is to have everybody doing the same thing, and if it's a case of some ambiguity" in U.S. courts, he said, "we should try to go along with what seems to be the consensus in other countries that are signatories to the treaty."
Sounds like a reasoned statement, but the conservative justice has been very outspoken when his more liberal colleagues consult foreign law when interpreting federal law and the U.S. Constitution. His comments Tuesday drew puzzled looks and even smiles from the audience.
When it comes to international treaty obligations by the United States, Scalia has articulated views somewhat similar to those expressed Tuesday, but not in such clear terms that appear to contradict his previous statements on the subject.
Those statements include his writing in a 2002 case, when Scalia dissented from the high court decision banning the death penalty for the mentally retarded. The majority opinion cited international condemnation of the practice.
"The Prize for the Court's Most Feeble Effort to fabricate 'national consensus' (against executing the mentally retarded)," wrote the justice, "must go to its appeal ... to the views of the 'world community,' whose notions of justice are (thankfully) not always those of our people."
And just last week, in a speech in Mississippi, Scalia noted, "If there was any thought absolutely foreign to the founders of our country, surely it was the notion that we Americans should be governed the way Europeans are. I dare say that few of us here would want our life or liberty subject to the disposition of French or Italian criminal justice -- not because those systems are unjust -- but because we think ours is better."
He said American judges who advocate use of international law in their rulings do it selectively, such as nations who have widely differing views on whether abortion is legal.
Scalia offered no further thoughts or explanations for his latest comments on treaty interpretations by foreign courts.