We are going to get to the bottom of Dan Rather's sweaters.

People want to know -- they have a God-given right to know -- why is Dan Rather wearing sweaters on the "CBS Evening News"? How many sweaters does Dan Rather have? Is Dan Rather related to Dan River? Is Dan River wider than a mile? Who picks out Dan's sweaters for him? What kind of person would ask such questions?

Dan Rather's sweaters are Topic A all over town. They're talking about it in network circles. They're talking about it on Madison Avenue. Bill Blass is talking about it. Top Senate aides are talking about it. High-placed White House sources might be talking about it. Birds do it, bees do it; even educated fleas do it!

Everybody in the universe is talking about DAN RATHER'S SWEATERS!

"I can't believe I'm talking about this," says Dan Rather in the course of being grilled with a Mike-Wallace-y mercilessness on the subject of his sweaters. But the fact is, ever since Rather started wearing a sweater under his sports coat on the "CBS Evening News," people within and without CBS seem to think he's been coming across as warmer, not just in the body temperature sense but in the trust-me, you've-got-a-friend, hello-out-there-in-television-land sense.

The cliche' about Rather has always been that viewers perceived him as cold, whereas with Unca Walter Cronkite, they felt like they were getting hot chocolate and cookies with the news. Lo and behold, Lord and Taylor, Ogilvy and Mather -- since Dan Rather started wearing sweaters, his ratings have gone up, and he seems safely if marginally in first place now in the all-important (unless you simply couldn't care less) network news wars.

Of course it has to be just a coincidence, right? Except for one thing: In television, you never know.

We've come a long way from the day when sweaters were strictly utilitarian cover-ups to be worn for warmth by old sea salts as they spun their yarns. -- Playboy Fashion Guide

Dan Rather knows his sweaters have been noticed -- not just by keen-eyed industry observers, but by fellow TV news people, and not just noticed, but emulated. "I'd like to think that nothing in television frightens me," he says, "and I say this not in any self-serving way, but suddenly it seems almost everywhere anchorpeople are wearing sweaters." And all because he started wearing them on his news show.

"God knows what would happen if you put a ring in your nose," Rather says.

How did Dan Rather become Dan Sweater? "I had a cold well before the great snows," he recalls, "and I'd been wearing the sweater around the office some, and I kept it on one night for the broadcast, and my wife, Jean, said later, 'Hey, that looks terrific.' I said, 'Well, it's pretty boring, I only have one sweater, but we'll ride with it for a while.' "

The rest of course is journalistic, cultural and fashion history.

But -- is Rather being completely honest about the origin of the sweater? Wasn't this part of a calculated move by CBS News to make him more lovable on the screen? Weren't there top-level meetings at which What Rather Wears was discussed for hours on end?

"That would give us credit for being smarter than we are," says Rather. "Now you get to something like the size of the matte graphic over my shoulder; we've probably had 1,426 meetings about that, which is 1,425 more than we should have had. But no, no top-level meetings about my sweaters."

One CBS News insider explains sweater psychology this way: Rather is so handsome, his perfection was putting some viewers off. The sweater makes him more accessible to all the poor Joes out there in their undershirts. We have to be realistic; you can do the best nightly newscast in network television, as Rather does, and win all kinds of approval, but to get those ratings, people have to like you and feel comfortable with you. Appearance counts, like the job counselors always say. Just don't be so gorgeous you make people hate themselves.

Determined to unravel this fascinating story down to its last thread, we interrogated Howard Stringer, who recently took over as executive producer of the "CBS Evening News."

"The sweater, I think, preceded me, but I'd be glad to take credit for it," Stringer said. "The fact is, Dan was warmer and more amiable than his image was long before I got here. But Dan and I have had no discussions of how he looks on the air."

There have been other cosmetic changes in the show, however, and people in the business are watching them all with magnifying glasses. For instance, Dan Rather's close-up is closer than Walter Cronkite's close-up was. The big question: WHY? What cunning McLuhan-y calculations went into that precedent-shattering decision?

"The real truth of that," says Stringer, "is that we've got an ugly set. The closer you get to Dan, the less you see the set." He concedes, though, that the closer close-up has made Rather "more relaxed" because there is less distance between him and the viewer; he doesn't have to stretch.

A new set is to be built, but that may be a year away, and Stringer doesn't know if he'll get an interim set or not. One obvious problem is that there is no place in the present set to put Bill Moyers, so he has to sit at Dan's desk like a pupil reading a term paper. It looks like a local newscast or, worse, like "20/20." Minds to be reckoned with are at work on matters like this.

Now CBS News has gone so far as to use promotional "bumpers" on its nightly newscast just like ABC does. Bumpers are the graphics before commercials that tell viewers what story they should stay tuned for. Stringer sighs. "Ah yes, the bumpers. Well, in our defense, I would say that the alternative to using the bumper is to go to a wide shot of the studio looking like the Starship Enterprise. So we thought we'd put that time to better use."

But none of this is as interesting as Dan Rather's attire. The sweater, the sweater.

For the record, Rather says that the first sweater he wore on the air was one his wife had given him 11 years earlier, but he now has five sweaters, three of them sleeveless, all bought "off the rack." The real question is how the other networks will meet this challenge. John Chancellor of NBC News might be considering a cardigan and a pipe but Frank Reynolds of ABC News is too old for sweaters. Maybe something in an ascot. Or a nice beret.

Tom Brokaw and Roger Mudd are probably being measured for sweaters at this very moment.

Rather has one big worry. Someday -- not soon, but someday -- it will be spring, and too warm for sweaters. He pauses. He ponders. He laughs. "If you're on a hot roll, what the hell?" he says. "If it takes wearing a sweater when it's 112 degrees, well, we'll turn up the air conditioning."