BOB ABERNETHY, anchor: The Supreme Court this week agreed to hear another Ten Commandments case. Pleasant Grove City in Utah has a monument to the Ten Commandments in a public park, and a small religious sect wants to put beside it a monument to its own seven principles. A federal judge said the sect had no right to do that, but the Court of Appeals disagreed. So now the Supreme Court will decide. We ask Tim O'Brien, correspondent and law professor to lay out the arguments.

TIM O'BRIEN (Correspondent, RELIGION & ETHICS NEWSWEEKLY and Visiting Professor, Nova Southeastern University Law School): Bob, the church's claim is not difficult to comprehend. It's says the city allows the Ten Commandments, it should allow its own monument. After all, a city park is a public forum. People gather there to have debates, to make speeches. And whatever the government does it must be neutral as to the content of what expression others are going to make.

ABERNETHY: So it's a free speech case?

O'BRIEN: There are certainly religious undercurrents here, but it is a free speech case, and the city agrees that in a city park it has to be neutral about what others will say. But they say in this case, it's not what others are saying. The city owns the park, it owns the monument. It's the city itself that is speaking, and that it does not have to be neutral about its own speech.

ABERNETHY: But if the Court upheld the city, wouldn't that be in effect saying it's okay for the government, the state, the city to discriminate, to endorse, to favor one religion over another?

O'BRIEN: Well, the practical affect would be to allow one religious monument and not another. That could be seen as promoting one religion over another. And if there's one thing all nine justices agree [on], the First Amendment requiring separation of church and state, prohibiting the government from establishing religion, prohibits the government from favoring one religion over the other. So if they do side with the city, yes, they're going to have some explaining to do. But if they don't side with the city, the argument is wherever you have a monument in a public park, anyone else will have the right to put up their own monument.

ABERNETHY: So if it's a World War II memorial someplace, then?

O'BRIEN: Someone could put up a statue to Adolph Hitler -- that's the argument that the city makes.

ABERNETHY: And, quickly, where do you think it's going to come out?

O'BRIEN: I think the Supreme Court is going to side with the city and say it has the right to choose what monuments it will have in its own city parks.

ABERNETHY: Tim O'Brien, many thanks.