RINCETON, N.J. -- TALL and slender with a flowing beard, dressed in a gray sweater and jeans, Brian Kernighan works his audience with a fast patter and a ready smile. The challenge he has set for himself is to demystify computing for a classroom full of liberal arts undergraduates at Princeton.

It so happens that Mr. Kernighan, 60, is a renowned computer scientist, a member of the Bell Labs team of the late 1960's and 70's that developed and nurtured the Unix operating system and the C programming language, innovations with a far-reaching impact on computing. He is also a best-selling author of technical books on programming that have sold millions of copies and been translated into more than 20 languages.

None of that really matters in this course, "Computers in Our World." The students are headed toward degrees in politics, history, English, art history, psychology and economics. Unlike many college students in the dot-com boom years of the late 90's, they have no plans to make a killing, or even a living, in the technology business.

Yet at a time when the corporate world and Wall Street are in the funk of a technology hangover, the students in Mr. Kernighan's class have a perspective that seems a levelheaded antidote to the prevailing gloom, based on conversations with a few of them. They have no illusions that computing is a silver bullet for the economy or a sure-fire path to riches. But they grew up surrounded by personal computers and cellphones. E-mail, instant messaging, Web searches, online shopping and swapping MP3 music files are second nature to them. They understand that computing is the modern tool used for everything from Hollywood special effects to unraveling the secrets of the human genome.

They don't believe that digital technology is inundating modern life at the alarming speed of "a Bengali typhoon," as Wired magazine once put it, but view it more as a rising tide whose impact is spreading steadily. Computing, they figure, is a good thing to know more about and to understand in a deeper way - while satisfying that pesky requirement that all Princeton students must take a course in "quantitative reasoning."

Mr. Kernighan, it seems, has made some encouraging progress with the fall semester class. The students do projects like making their own Web pages and writing a few simple programs. And they speak of a new appreciation for computers and moments of epiphany along the way.

"I've always used computers, but I had no prior knowledge of what goes on inside them," said Lori Piranian, a freshman. "Taking the course has given me a new respect for computing. It's amazing what goes into a computer and the history of how we got to where we are now."

Mr. Kernighan's course is a kind of intellectual smorgasbord, combining public policy - like technology's impact on privacy, copyright and antitrust matters - with large helpings of practical knowledge of how things work, from operating systems to disk drives. Still, some students said that the single class session that made the strongest impression was Mr. Kernighan's lecture on binary numbers, also known as binary digits or bits. In his talk, Mr. Kernighan explained that everything a PC does - handling text, music or video - is all just a matter of processing 1's and 0's to the machine. The difference between today's multimedia notebooks and the room-size calculators of computing's early days, he notes, is mainly faster bit-processing engines and increasingly clever software.

"What you come to understand," said Joseph Falencki, a junior, "is how simple, yet how complicated, a computer really is. That was the 'aha' moment for me."

After a late-October class, Mr. Kernighan explained that his goal in the course was to impart an intelligent skepticism about computer technology, an informed sense of its possibilities and limitations. "And you can't do that in the abstract," he said, which is why programming and projects are essential elements in his course. Smiling, he mentioned the often-quoted line from the science-fiction writer Arthur C. Clarke: "Any sufficiently advanced technology is indistinguishable from magic." A wonderful phrase, Mr. Kernighan said, "but there is no magic."

Mr. Kernighan acquired his taste for teaching while on a year's leave from Bell Labs in 1996 at Harvard, where he taught an introductory computer science course. "I got an enormous kick from it," he said. "To me, it felt the way it must be for an actor onstage - the rush when it clicks, and the letdown when it doesn't."

So four years later, when Princeton asked him to join the faculty, Mr. Kernighan agreed and said he wanted to teach computing to liberal arts students as well as his Advanced Programming Techniques course in the computer science department. His former colleagues were not surprised that he turned to teaching, including teaching nontechnical students.

"It's pretty clear that Brian has a continuing interest and commitment to education - writing well-read books was how this was first expressed," said Dennis Ritchie, creator of the C language. Indeed, the best-read of his books is "The C Programming Language," written with Mr. Ritchie and first published in 1978. To professional programmers, the book is known simply as "K & R." Most of the text, the programming examples and problems came from Mr. Kernighan, whom Mr. Ritchie calls "a fluent and charming writer on technical subjects."

Mr. Kernighan genuinely enjoys translating his technical field and explaining its significance for humanities students. But in his understated way, he also thinks it is something that must be done and perhaps contributes to the greater good. "For better or worse, the people who become leaders and decision makers in politics, law and business are going to come from schools like Princeton," Mr. Kernighan said. "What I'm trying to do is give them some of the tools of the trade that will make it possible for them to think intelligently about this technology for themselves."

Such sentiments place Mr. Kernighan within the camp of computer scientists who believe that computing deserves a place in general education.

It is a point of view with a rich history, dating at least as far back as the 60's at Dartmouth. As the impact of computers spread through society, two professors, John G. Kemeny and Thomas E. Kurtz, decided that Dartmouth students should have hands-on experience with computers. With the university's full-fledged support, they designed a computer time-sharing system and a simple programming language, Basic (Beginner's All-Purpose Symbolic Instruction Code), which proved to be an enduring contribution to computing. Stripped-down versions of Basic became the programming choice of the microcomputer industry in the mid-70's. One variant, Microsoft Basic, was the founding product of the world's biggest software maker.

Some computer scientists have pushed ever since to make computing a central part of a liberal arts education. In 1999, a report by the National Research Council, an arm of the National Academy of Sciences, titled "Being Fluent with Information Technology" called for a broader definition of computer education that would emphasize not just practical skills but also concepts, principles and ideas. That is, precisely the sort of course Mr. Kernighan is teaching at Princeton.

In an October class focusing on computer operating systems, he began with a newspaper article on the challenge Microsoft faces from Linux, a descendant of the Unix operating system that is distributed free and written and debugged by a volunteer community of programmers. (Incidentally, Mr. Kernighan gave Unix its name back at Bell Labs in 1970.) The governments of China, Germany and other nations are using and promoting Linux as an alternative to Microsoft's Windows operating system. "It's that important to them, to become less dependent on Microsoft," Mr. Kernighan said. "To do that, they will use Linux instead of a program written by one of the premier technology companies in the world."

Twenty years ago, Mr. Kernighan observed, "Only nerds cared about operating systems." Now, he added, the subject is a public-policy issue, even front-page news occasionally.

He traffics in metaphor and analogy. The operating system is a juggler, keeping several different programs running at once - like balls in the air. He compares file folders, which show links to files on the hard disk, to a library card catalog, which "is not the books but the structural information that tells where things are,'' like the file folders in a computer system.

There is no mention in class of Mr. Kernighan's distinguished background. But most of the students have run a Google search or two on Mr. Kernighan and seem somewhat impressed. "He wrote that book on the C language back at Bell Labs a long time ago, before I was born," said Ms. Piranian, who is all of 18.