Tony Auth was watching TV one day last year, minding his own business, when on came the Democratic National Convention.

"It was the night of Carter's acceptance speech," Auth remembers, "and as he was making his entrance from the floor with the band playing 'Why Not the Best' and everything, I said to myself. 'This guy has thought of every little detail, he's as much a simple farm boy as I'm going to fly to the moon.'"

And that experience which resulted in a sketch of Jimmy Carter with a cross-section of a computer for a brain, is the answer to the thing that Tony Auth, Pultizer Prize-winning cartoonist for The Philadelphia Inquirer and 70 other papers, hears the most: Where do you get your ideas? In fact, just hearing that again makes Auth, a lively, jumpy man, plop his head right on the table with a woeful shrug.

Of course that's not the only thing that Auth, here to speak on cartooning at the Smithsonian, hears. "I get a lot of hate mail, but it's predictable," he says, nonchalant. "A lot of it is people saying 'screw you' to me the way they think I said 'screw you' to them. Not a serious dialogue at all. Or else they claim I'm sort of taking advantage of free speech, that I ought to go to Russia, where I'd be shot, and that if America was any good, I'd be shot here, too."

One of the biggest outpourings of mail came when Auth too sick and The Inquirer ran a little box saying "Tony Auth is ill."

"The paper got all kinds of letters saying. 'We knew it, it's been obvious for years.'" Auth says happily. "I told my editor the next time that happened he should run a box saying 'Tony Auth is sick, sick, sick.'"

It's not so much that Auth has developed a professional impermeability, though he has, as his feeling that specific reactions to his cartoons, either positive or negative, are not as important as people just reacting, period, and not going "Eh."

"The ideal is to make people see something in a new light, to say 'Oh, yeah, that's right,'" he explains. "What we call information is really a glut of some facts, some public relations, some nonsense, some propaganda. I try and cut through it, illustrate what's really going on. The criticism of a cartoonist simplifying an issue is a criticism. I hear from people who think I haven't simplified it correctly. Otherwise they say, 'Wow, you really cut trhough all the crap and got right to the point.'"

Which is not to say the absolutely nothing upsets Tony Auth. Working from inaccurate information is his worst fear, illustrated by the time immediately after Allende's overthrow in Chile when he did a cartoon depicting it as a middle-class people's revolution. Even at this juncture, thinking of that makes him groan audibly.

Almost as bad is the problem of being misunderstood of being too subtle. A cartoon on nuclear proliferation fizzled because many people either weren't familiar with the symbol for nuclear energy of hadn't seen the sorcerer's apprentice scene from "Fantasai" on which it was based.

And when Auth drew Henry Kissinger as a bovine sort of animal being worshiped on Capitol Hill, everyone got confused. Was it a golden calf or a sacred cow? One cautious newspaper called to ask if if could excise the udders, and another, Auth swears, "wanted to know what I was trying to imply by drawing Henry Kissinger with four penises."

Besides expressing curiosity about the source of his ideas, most people meeting Auth seem surprised that he's as young as he is, namely 35. "The age that seems right is 56," he says, smiling. "And every once in a while when I use a credit card people say. 'Oh, is your father the cartoonist?'"

Though he's drawn for as long as he can remember, it took Vietnam to turn Auth political. "I was a medical illustrator, a political, and if it wasn't for the war, chances are I'd be at John Hopkins or someplace right now, being very happy.But there was a chance I'd be drafted so I checked things out and I got gradually convinced that the war was stupid, obscene, wrong."

So Auth began doing one political cartoon a week for a Los Angeles underground paper called Open City, moved on to the UCLA Bruin and, in 1971, to The Inquirer, where he says his biggest problem is "figuring out something to say five days a week, 50 weeks a year, functioning on days when you'd really rahter not, when you're not inspired and there's no news."

Auth feels a kinship with other political cartoonists, both past and present. He talks of how they are "caused by periods of great social upheavel" and speaks admiringly of English cartonist David Low:

"You've got to respect this guy incredibly. He knew what was happening, he was right, and if people had acted on his work, maybe World War II could have been prevented."

The one essential factor in all this, Auth feels, is a sense of outrage. "That's the thing you gotta have," he says. "You have to be capable of reading something and saying, 'I don't believe that,' and then translate that into a drawing. Those are the most satisfying cartoons."

And though Auth is admittedly "free of the necessity to be objective I'm allowed to reach conclusions.I get to be irrecerent," that doesn't mean he does without any standards at all.

"I care very much about being unfair. I don't want to be unfair," he says with great emphasis, "but I don't want to shy away from asking the hardest questions I can think of.

"There are a lot of timid newspapers, and they don't have cartoonists of the caliber of Herblock or Oliphant. They want control they don't want to have to deal with anybody they might disagree with, and any cartoonist who's any good is always thinking to ask the uncomfortable questions."

And as to his own personal cartooning philosophy. Tony Auth simply grins and says, "Once in a while when they're expecting a chuckle, I knee them in the groin."