If bad television did not drive out good television, then ABC would not be the No. 1-rated network today and the other two networks wouldn't be playing games of how-low-can-ye-stoop to compete. Clodpated foolishness in TV drives out even erstwhile stabs at seriousness. This situation is going to get worse, not better, in the months ahead.

The difference between the amount of cheap comedy on the air and the amount of moderately intelligent drama or informational programming is TV's reality gap. TV's reality gap is getting wider. Of 18 new series announced as mid-season replacements by the three networks, 15 are comedies or advanture shows with high comedy content.

NBC's "Lifeline" was cut, as everyone knew it would be, and the network has nothing to offer as a tony or high-minded replacement. The highest minded things will get in a new weekly series on NBC is "Little Women," described by the network as a "family drama." ABC will introduce three new conedies and "Salvage 1," about a "crew of retrieval experts who tackle seemingly impossible tasks" -- perhaps they can work on redeeming the honor of television -- and CBS will introduce four new situation domedies, one "comedy-adventure" and a revamped Mary Tyler Moore comedyvariety hour.

CBS continues to lead the race in wildly worthless comic-book TV; to "The Incredible Hulk" and "Wonder Woman" it will add, on Jan. 19, the two-hour pilot for "Captain America," another tabloid Galahad. NBC responds one night earlier with a one-hour "Challenge of the Superheroes" featuring Adam West and Burt Ward as Batman and Robin, Bill Nuckols as Howkman and Barbara Joyce as The Huntress. America, put on your thinking cap.

Of course it is inevitable that television, especially prime-time television, be primarily an entertainment medium. So was radio in its day. We viewers are not shirking our duties as decent citizens because we slink home at night and turn to commercial television for soothing frivolity -- or to public television for soothing boredom.

On the other hand, it hardly seems unfair to expect that now and again this diet of junk food might be spiced up with a vegetable or two Maybe a fruit salad. A little chicken soup -- it wouldn't hurt. Too rarely, though, does a deep of reality invade the nonstop laugh track of the sitcom.

One of these days, we human beings of the planet Earth are going to be held accountable for television. We are going to have to explain how a mass medium with its potential for social welfare became a nation's kiddiecar. TV doesn't just sell Tickle. TV is tickle.

Ah but look -- the networks might say -- in recent nights there have been several prime-time documentaries. Only last night NBC wiped out its entire schedule for a three-hour inquiry into "The American Family," such as it was. The interesting thins is, these holiday and post-holiday weeks happen to be among the lowest viewing weeks of the year. The face-saving documentaries are thrown on when a newtork feels it has the least to lose.

In truth, documentaries do not draw the gigantic audiences that even the flimsiest of fantasies can attract. CBS programming executives committed the self-defeatist folly of scheduling it for the night after Christmas, but the CBS News report "Anyplace but Here," a study of changing approaches toward the treatment of mental illness, was fascinating, moving and invaluable. It was produced by Tom Spain and narrated by correspondent Bill Moyers.

This wasn't just an examination of an "issue" -- this was a vital essay on human behavior.

But this is apparently a topic of interest to relatively few American TV viewers.

"Anyplace but Here" got an 11.4 Nielsen rating and a 19 percent share of the available viewing audience the night it was shown. On NBC, the lame-duck, already canceled series "Grandpa Goes to Washington" did better -- a 13.1 rating and a 21, share. And on ABC, the old one-two of "Happy Days" and "Laverne and Shirley," though both were in reruns, earned a 28.9 rating and a 48 share.

This mumbo-jumbo from Nielsen can be translated into fairly discouraging numbers of tuned-in homes. If we combine the 21.5 million homes tuned to ABC's jive and the 9.7 million tuned to NBC's hogwash we get 31.2 million homes that opted for funsy-wunsy while only 8.5 million homes braved a dose of the-way-life-is on CBS.

A few days earlier, another excellent CBS News documentary was also dumped into the low-viewing period and also fared poorly in the ratings. "But What About the Children," a study of a family split by divorce and how two young sons were coping with this crisis, came in 59th among he week's 63 rated network programs.

What did worse? NBC's worthwhile "Weekend," the expiring "Lifeline" and a filmed revival of the TV classic "Amahl and the Night Visitors."

Perhaps viewers have to be tricked or seduced into watching any nonfiction television that isn't a football game. ABC News has tried making documentaries on glitzy, volatile subjects and giving them titles that might have been churned out by a lowbrow Hollywood press agent in an attempt to hook a few more Nielsen homes.

A widely praised ABC report on street crime in the Bronx was titled "Youth Terror: The View From Behind the Gun." This must have grabbed the "Starsky and Hutch" crowd because the show achieved unusually high ratings for a documentary.

ABC has also televised documentaries with titles like "The Politics of Torture" and "The Mysterious World of the Supernatural: Fact, Fraud or Faith?" They may be going after the National Enquirer audience with pitches and subjects like this, and neither of these programs was a distinguished piece of journalism, not by a long shot.

There must be better ways to lure viewers to dicumentaries to make television less of a sprawling fantasy island, and to skew it away from the tots and back toward the adults. Actually, there's a very simple way, and ABC could do it: just upgrade all the programming until it is as good as it now is bad. The other networks would be forced to follow suit.

And would all the dopes and dumbheads complain that TV had become too intelligent for them? No. We know for an undeniable fact that the dopes and the dumbheads will watch television anyway. That doesn't mean they should have the right to ruin it for the rest of us.