Television is leading us into a new age of Dumb. Show after show presents us with characters whose stupidity is supposed to make them comic, adorable, even enviable. The happy punk has become TV's most popular sit-com cliche, and it reflects a philosophy that says it's all right to be stupid as long as your head is together.

Obviously the Fonz on "Happy Days" made the stereotype fashionable, and now many programs feature Fonzian toughs who are ignorant, uneducated and unintelligent, but who earn the adoration of others by being cool and taking command of situations through the threat of force.

John Travolta as Barbarino on ABC's "Welcome Back, Kotter" - a program that celebrates communal as well as individual punk clowishness - is the most obvious Fonz clone running amok on the airways, but there are many others, at least one of them a member of ABC's pitiful new low-brow comedy "The San Pedro Beach Bums."

ABC leads the way in reverence for this character type, but the CBS comedy "Busting Loose" has its little Fonzie on the premises as well. Like the other Fonzies, this one is not only adorably dumb, but his dumbness is seen as a sexual asset: he has no trouble getting girls. In the land of the New Dumb, it's sexy to be an inarticulate clod.

The highest-rated summer series this year was "Szysznyk" on CBS. One episode of this comedy centered on the ability of the Fonzie figure, "Tony" (Scott Colomby), to make it through 14 years of public school education without ever learning to read or write.

Tony was at first embarrassed when his inability was revealed (a hopeful sign?) but he turned out to be the hero of the piece for having engineered such a clever con for 14 years; he'd hired literate pals to write his term papers for him. In the end it was decided that though he was an ignoramus, his head was together and that's what counts, right. Beside, he was eminently successful as a heartthrob.

Allen Rucker, a producer with the ambitious Los Angeles video group "TVTV," calls this new trend "Dumb Chic" and thinks it has developed partly because it's now considered sexist to portray women as "dumb blondes" on comedies. Even the Georgia Engel charater has wisted up a little in the step from the late "Mary Tyler Moore Show" to the current "Betty White Show."

Male dumb symbols also tend to be male sex symbols, Rucker notes - and perhaps this is just a case of equal time for men after years of slandered women in pop entertainment. "In series after series, the Barbarino character isn't just dumb but a leader; he's a leader for being dumb," says Rucker. "These shows tell you it's necessary to be dumb to be cool."

The success of the movie "Rocky" put the final imprimatur on the virtues of dumbness and fastness with fists. A stereotype hero seemingly dead was gloriously exhumed. Commercials have always been dumb, of course, but now we see the "Rocky" and Fonzie influence there as well, with athletes or leather-jacketed types threatening violence to those who don't agree with their worship of a product.

Muhammad Ali is certainly not a symbol of dumbness, and yet his commercials for "Gino's" include the clear implication that we'll have to answer to him if we don't concur on the virtues of a particular hamburger. Ads for shaving creams, deodorants and most of all beers carry this suggestion even further. We're being bullied, not coaxed, into obedience and compliance.

Women's lib was supposed to help destroy the idea that a guy can't be manly unless he's also a little bit of a dumb brute. Suddenly the concept is returning to fashion, perhaps as a reaction to so much media talk about homosexuals and the apparent influence of homosexual lifestyles on mainstream society.

There is more to the New Dumb, though, than the re-emergence of the hero oaf. Television programming seems more dominated than usual this year by foolish, proudly witless escapism. The new season is the silly season, glutted with such strictly non-think new shows as "The New Adventures of Wonder Woman," "Carter Country" (a ratings smash in its bow last week), "Operation Petticoat," "The Man From Atlantis" and "The Love Boat."

Last week, two days after CBS aired a 90-minute pilot for a childish series about the comic-book cut-up "Spider-Man," ABC offered a two-hour TV movie, "Curse of the Black Widow," about a woman who turned herself into a giant spider and drained the blood out of innumerable screaming victims.

One thing has become apparent from this quick drift into jibberish: threshholds of consciousness mean nothing in television. Many of us thought that the success of "All in the Family" would put an end to irrelevant or at least non-humanist comedy shows. With "Happy Days" and all its reactionary imitations, ABC has kicked his theory to bits.

After the progressive beach-head established by the semi-realistic CBS series "M*A*S*H," it looked as though military comedy would never be the same; that the days of war-is-cute were over. Only last week, however, ABC introduced us to "Operation Petticoat," which is Olsen and Johnson Go to War all over again; it makes Abbott and Costello's "Buck Privates" seem sophisticated by comparison.

ABC is in fact the leader, undisputed, in dumb television and the proliferation of punk heroes. With this in mind, one can fondly recall the words of ABC Entertainment president Fred Silverman, who declared piously last summer that TV has a mandate "to illuminate the problems of society" and that "now, more than ever, the problems in our society need illumination."

One of the crucial societal problems illuminated in Silverman's "Beach Bums": a fat guy and a skinny guy go to a nude beach and have their clothes stolen.

In a spirit of wildly unwitting irony, ABC titled a recently aired 15-minute promotion film for its new season, "Television Grows Up."

It would be naive to think that TV's glorification of the cheerfully stupid doesn't affect audience attitudes and reflect wider trends in society. Religion, for one. In a Saturday Review piece on "The Jesus Mania," writer and preacher's son Dwayne Wells finds the current pop-religious fervor sweeping the nation marked by "the persistent element of anti-intellectualism, the retreat from reason back to mysticism and emotionalism."

"Given the trends in American life," Wells writes, "it is reasonable to conjecture that 'church religion' might ultimately be replaced by disembodied voices and faces on radio and TV sets. The Jesus movement, with its demonstrated affinity for pop culture, would be right at home in such a setting."

You put all this together and it begins to look as if appeals to reason will be falling on more deaf ears and blind eyes than ever. Perhaps it will soon be possible, when watching television, literally as well as figuratively, to worship at the Shrine of the New Dumb.