RICHARD P. Feynman's constantly amusing memoirs reminded me irrestibly of Huckleberry Finn. Imagine, if you can, that Huck had grown up in Far Rockaway, not a river rat but a precocious little boy with a screwdriver dangling from his pocket, repairing radios when he was barely old enough to know a tube from a condenser.

Imagine that Huck's father was not a drunken thug but someone who encouraged a questioning attitude about everything.

What you might get, with luck, is an intriguing blend of uncouthness (recall Huck's instinct to light out for the wilderness at Aunt Polly's approach) and genius.

My heart sank, I must admit, when I read that these reminiscences had been transcribed as spoken. But that was before I read them. In fact, the racy, colloquial, wiseacre voice is perfect for these often bizarre, smart-aleck anecdotes. You might think, in fact, that Feynman has spent much of his life fleeing his own Aunt Pollys, and so in a sense he has. He draws his title, for instance, from what the wife of a Princeton dean said when he asked for both cream and lemon in his tea. "You must be joking" seems a refrain threaded through all his adventures.

When he isn't joking, Feynman is a distinguished theoretical physicist, a Nobel laureate (though, by his account, a reluctant one: He may be the only recipient of that great prize who, on learning that one backs away from a king, planned how he might jump backward from the king of Sweden).

The autobiographical Feynman is vague to the point of evasion about the theoretical accomplishments that won him such exalted notice. Even when he is reminiscing about his work at wartime Los Alamos, the stories are not about physics but about people. The scientific inquiries he prefers to talk about are of the impromptu sort anyone might try but that few are so unconventional as to think of: comparing the human sense of smell with a dog's by trying to guess which of a row of books had recently been handled; examining, for hours, the trails ordinary ants leave across a floor when going to and coming from a food source; and, yes, demonstrating that urine flows by pressure (rather than by gravity) from the bladder by performing while standing on his head. Feynman also has played and marched with a marimba band in Brazil. He has investigated Mayan astronomy. He has played the bongo drums in accompaniment to a ballet. He has painted well enough to put on a one-man show. He has frequented the gambling dens of Las Vegas. There seems little of an unexpected sort he hasn't done.

If this delightful book seems, at first glance, to violate the usual expectations about Nobel-prizewinning theoretical physicists (and is surely intended to do so), look more closely. Beyond the first impressions, you find that Feynman's bumptious refusal to take any proposition on second-hand or hearsay evidence, his pristine curiosity about how things work, is closely related to the gifts that underlie distinguished science.

We need not compound the endless, ageless theorizing about the essence of science. But it is certain, at a minimum, that a good professional scientist cannot afford to take anything for granted. Most of the rest of us take much for granted much of the time. We might do less of it if we took seriously at least two brilliant chapters in this book.

ONE IS Feynman's account of what he discovered about the study of physics in Brazil, while a visiting lecturer there in the 1950s. He noticed that the students seemed to "know" their physics in a propositional way and rarely asked any questions, indeed seemed impatient when questions were called for or asked. He was puzzled, and as usual took a closer look. What he found was that the Brazilian students were only memorizing the abstractions of physics. They had no idea what the words meant or how they might be experimentally applied or tested. Physics in Brazil was an empty exercise in mnemonics; it was conceptually and experimentally vacuous. Feynman, characteristically, told his Brazilian students and colleagues so.

Another chapter, concluding the book, is a commencement talk at Cal Tech, where Feynman has taught since the early 1950s. It is a discussion of the elementary demands of intellectual honesty, rigor and diligence essential to good science. Some of the rules ("a care not to fool yourself," for instance) seem deceptively obvious. Yet Feynman, sadly, is right in saying that what he calls "cargo-cult science," a credulous form of science more akin to magic than to inquiry, is more usual. His formulation of the first principles of experimental learning is so fine that it should be required reading in every American school. Its usefulness is hardly limited to science. When he says, for instance, that "the idea is to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction," I find myself noting: "Good rules for journalists too."

What would become of civilization as we know it if everyone were as unconventional, as insistently rational, as Richard P. Feynman I have no idea. That it would often be disconcerting is suggested by one of his stories. As a distinguished California scientist he was asked to serve on the state textbook commission, to help select books for the schools. Customarily such commissioners sampled allegedly "informed" opinion, then made their choices. Feynman, however, obtained all the books and read them. He found, in some caes, that these schoolbooks "said things that were useless, mixed-up, ambiguous, confusing, and partially incorrect."

Credulity and the instinct to go along with what is usual are perhaps more natural human attributes than skepticism and the instinct to challenge well-worn, comfortable routines. And surely for most social purposes that is not altogether regrettable. But all of us could stand some stretching in the Feynman direction. It might even be fun.