These are the things Michael Douglas is into these days; Marriage. Monogamy. Running. Working. Playing with his kid. Not smoking. An occasional binge. And Optimism.

Normality -- what a concept.

"Maybe," says the man who brought you the mental institution as metaphor in "One Flew Over the Cuckoo's Nest" and a chilling preview of coming reality in "The China Syndrome," "that's what I'll get into next -- you know, a sort of Rev. Billy Graham routine -- 'Repent! You too can play by the rules. You too can learn to lust only in your dreams and talk dirty on the telephone. Work hard and find joy in titillation. . .

"That's me," says Michael Douglas, suddenly serious behind his mustache. "A Protestant Ethic man all the way."

Douglas was in town yesterday to plug his new movie, "Running," due out in November, all about a 34-year-old man whose fear of failure has paralyzed him out of several careers and who is bent on proving himself by running in the Olympic marathon, a kind of Rocky Takes to the Road.

"Sometimes the hardest thing in the world is to be yourself and do what you want instead of what people expect," he says over a mountainous shrimp salad. "I guess in that respect, I relate a lot to the character I play."

This is about the only way Michael Douglas will refer to what it is like trying to make it and be Kirk Douglas' son at the same time, and maintain a reasonable amount of consistency on the subject. From there, he proceeds to, "It wasn't half as hard as reporters like to make it into." Which is followed by, "You get no credit for your own identity. People aren't happy for you, they don't give you credit for your own successes. You find yourself doubting your own abilities. Every minute, they're ready to lock you right in and nail the coffin shut. I just want to keep them guessing."

There is a pause and a deceptive grin. "I really enjoy hostility," says Douglas. "It keeps me going better than just about anything."

At this point, it would seem that Michael Douglas would have very little to feel hostile about. The five years it took to bring "Cuckoo's Nest" to the screen resulted in five Academy Awards. Three Mile Island made "The China Syndrome" look like the handwriting on the wall. Douglas remembers the moment he heard about the near disaster in Pennsylvania. "It was a religious experience for me," he says now. "The coincidences were so eerie. My wife came running back and asked me if I'd heard the news, and when she told me, this thing, this feeling just went up and down my back. The first treatment for the movie, written eight years ago, had been called "Three Mile Danger." It really scared me. I couldn't deal with the similarities."

Now Douglas has found himself a plateau where the view is crowded with everything but regret. . ."I'm glad I had all the experiences I did," he says. "The '60s were so unambiguous, everything was either right or wrong. There was a real feeling of living on the edge. But my relationships really suffered -- it was only after I had achieved a certain success in work that I could think about settling down. Now all my friends are still as crazy as ever, but they're exploring monogamy and in-depth relationships."

Now, Douglas is settled down in Santa Barbara with his 23-year-old wife Diandra, who was a Georgetown University student until she met Douglas at party the day before Carter was inaugurated. They have a 10-month-old son, Cameron. "I just realized the other day that he'll be 21 in the year 2000," Douglas says. "It's hard to imagine what his life will be like."

Douglas' life will center more around acting than producing for a while, he hopes, with the possibility of a romatic movie costarring Jill Clayburgh in the future. But most of the acting jobs he has been offered he says, have been "a lot of crap. There's a lot of mini-moguls out there who are all ex-SDS members saying that what they've got is my kind of picture. And none of them do."

He looks as if he has been drenched in autumn -- a pink face above the recently-grown mustache, a corduroy jacket, and a manic mood that sweeps over his face like a gust of wind. He keeps his contradictions perfectly balanced to the end. "I'm really looking forward to the '80s," he says. All the '60s people are coming to power. There's a real frontier spirit out in the country, and, I know I sound dumb saying this, but it's what kept America strong. I think it's going to be a tremendous time," says Michael Douglas cheerfully, "unless, of course, there's a war. There's a lot of people out there just waiting to punch somebody out."