First I must confess. There is a juice glass from the Arizona Biltmore in my kitchen cupboard, a blue and white towel--with Hebrew lettering--from a Jerusalem hotel in my bathroom and a small china ashtray from the bar atop Seattle's Space Needle in my living room.

I never paid for any of these items. They simply caught my fancy and made their way into my suitcase. But, like Richard Nixon, I protest: I am not a crook.

The criminal code, however, disagrees. "Taking the property of another--knowing it to be the property of another--is a crime," notes Franklin Zimring, director of the University of Chicago's Center for Studies in Criminal Justice.

"So why doesn't this sort of 'Howard Johnson syndrome' feel like a crime? Because everybody does it. People know they're not going to get arrested for swiping a glass or an ashtray. If the restaurant owner stops them and calls the police, the police will tell the person to put it back."

Most people don't consider their petty pilfering to be stealing, says psychiatrist Robert Custer, "because they rationalize what they consider to be a good reason to justify their action." For example:

* A $30,000-a-year administrator walked out of a large drug store chain with a lightbulb she didn't pay for because the store manager was "incredibly nasty" when she tried to get a refund on a previously purchased item.

* A New York editor slipped his silverware into his jacket pocket at a banquet because the speaker was so offensive, the waiters so rude, the food so bad and the cost so high.

* An inebriated jogger stuffed a large cocktail glass under his sweatshirt so he could finish his drink at home.

* A disgruntled federal employe took home pads, paper clips and pencils from the office each week because she felt underpaid and overworked. ("I'd like to 'band' government pens like they do pigeons," says one bureaucrat, "and see how long it takes one to migrate across the country.")

Most of this petty thievery "is done impulsively," says Dr. Custer, who specializes in "impulse disorders" such as pyromania and kleptomania. Unlike kleptomania, which involves "larger-scale theft by someone who steals because they can't help it," he says minor pilfering "is not a lifestyle or a mental disorder . . . nor a steppingstone to kleptomania."

A common reason why someone who is well off might steal an object of little value, he says, "is displaced hostility. The person may be mad at a spouse and take it out on the hotel.

"A woman may feel her husband should have given her a present, so she gives herself a present of the vase on the table. Most of the time they do it when under tension. The act reduces that tension."

A frequent rationalization, says Dr. Custer, "is that they've been cheated by a huge organization." Someone who wouldn't dream of taking silverware at a dinner party in someone's home, he says, may have no qualms about slipping a teaspoon in their pocket when dining at a big hotel.

"They feel like the little guy," he notes, "up against greedy big business. Especially with inflated, high prices, they feel they've paid for it. It's almost a self-righteous thing. They feel entitled to the object and are oblivious to the fact that they're taking something not theirs.

"And sometimes it's seen as a little game . . . a way to bring a bit of excitement into an otherwise dull life."

While "nearly everyone does this at one time or another," says Dr. Custer, "those who do it on a fairly consistent basis are often meticulously honest, very sensitive, kind people . . . who know inside that what they are doing is wrong. If they are caught they feel terribly humiliated."

Most are women, he notes, possibly because they are under more tension, lead less exciting lives or feel victimized more than men. "I don't see it as a threat to society," he says. "But they do end up with a lot of ashtrays and towels."

Thievery--however petty--adds up, note the hotel and restaurant industries. "The towel loss at one major U.S. hotel chain was in excess of $3 million a year," says Ray Ellis Jr., security specialist for the American Hotel and Motel Association. "These costs are reflected in higher-priced rooms."

Hotel guests -- and employes -- have stolen, he says, "anything that isn't nailed down. One hotel put little plaques behind pictures that said 'A piece of fine art has just been stolen from this wall.'

"In one motel someone turned off the water and stole a commode. In another, when the maid came in in the morning, she found that everything--bed, drapes, carpeting, furniture--had been carted up and hauled away."

Although some pilferers insist ashtrays are meant to be taken as souvenirs, Ellis says this isn't true. "Did they ever consider that the hotel's name is on the ashtray to keep it from being taken?" he says. "More and more hotels are using plain glass ashtrays because they don't disappear as fast."

Some restaurants discourage pilfering by offering for sale those items--like novelty glasses--that are frequently ripped-off, says Elaine Raffel of the National Restaurant Association. "One reason why waiters at a lot of restaurants offer you fresh pepper," she adds, "is that pepper mills are the most-often taken items--so they prefer not to leave them on the table."

Pilfering by employes is also wide-spread. "The equity theory is frequently in play," says University of Minnesota sociologist John P. Clark, who is completing a project on theft by employes for the Justice Department.

"In situations where the employes think their supervisors and the organization in general isn't treating them right, you'll find higher levels of theft."

While unmarried males aged 18 to 30 are the most likely culprits, notes Clark, "our conclusion is that generally one half to two-thirds of employes will admit being involved in this kind of thing. And that's a conservative figure."

"It's related to a phenomenon some call the 'hustling mentality,' " says sociologist James Short, director of Washington State University's Social Research Center. "You see an opportunity to get something for nothing, and you do it. In our society, that's often considered the smart thing to do."

It appears, then, that there's a little bit of larceny in us all. (Which may explain the difficulty Diogenes had in finding an honest man.) And that disturbs Father Robert Paul Mohan, who teaches "contemporary moral issues" at Catholic University.

"Theft is a moral question," he notes. "And while this kind of whimsical theft seems trivial, the mindset behind it indicates a growing moral insensitivity . . . and a rapacious refusal to recognize someone else's property.

"People seem to think prevalence constitutes justification; that because everyone does it, it's okay. Particularly when dealing with a depersonalized institution. Since they don't see the victim, they may deny that there is a victim.

"Psychologically I think it's a rather bad habit. The moralists talk about the 'slippery slope.' You make one exception to a rule, then gradually find yourself utterly indifferent to the principle involved."