BOOKS OF THE TIMES; The Computer World, Inside and Out

''The Future of Ideas'' (no less), by Lawrence Lessig, is about the Internet today, where it is going and where it ought to go. His soft-spoken sobriety (not reflected in his choice of title) is a breath of fresh air in a crowded field where most authors would rather shout than talk.
He is a fund of clear, clean, useful information. If you need to know where ''MP3.com'' or ''Napster'' or ''CPHack'' or the Web in general stand today, Mr. Lessig is your man. His brief explanation of what ''consent decree'' means is the best I have ever read. Actually I couldn't care less what it means, but I had better know, and so had we all. This book is a public service.
But it is not merely that; it makes an argument, and here the results are mixed. The broad claim seems innocuous. The author boldly endorses ''free speech, privacy, access to content, freedom from excessive regulation''; he says that ''the original Net'' valued and protected these things, and that the Internet should continue protecting then, whatever it turns into.
Some of his specific assertions seem convincing and important, for example, about the future of copyright in the cybersphere. The Internet makes a new and higher degree of control possible; lawyers can monitor postings on Web sites as they cannot in, say, dorm rooms (we hope). ''Increasingly,'' Mr. Lessig writes, ''as activity that would be permitted in real space (either because the law protects it or because the costs of tracking it are too high) moves to cyberspace, control over that activity has increased. This is not a picture of copyrights imperfectly protected; this is a picture of copyright control out of control.'' To allow copyright controls to be tightened merely because it is possible to tighten them risks choking off the creation of new ideas and the dissemination of old ones.
The author's larger argument in favor of a free-and-open Internet, versus one where a few big companies have disproportionate power, is sensible and appealing. But the counterarguments he doesn't mention are distracting -- ghosts in the woodwork. The reader feels, sometimes, as if he were trying to concentrate on a magic act while the backdrop burns down.
Patents on software (for example) are in bad odor with Mr. Lessig, who notes without irony that Bill Gates has doubts about them, too. Well, Mr. Gates might. Software patents are the one weapon that penniless inventors and small companies wield against the Tyrannosaurus rexes that dominate the industry. A software patent creates an asset out of thin air. Investors do not put their money behind mere software ideas because, should the idea prove good, some large company (Microsoft is not the only candidate) can send a great, swarming army of programmers to munch the thing down and reproduce it fast. Mr. Lessig seems oblivious of the danger.
But on other issues, he is less than fair to the T. rexes. He is a booster of free software. ''The most important space for innovation in our time was built upon a platform that was free,'' he writes, and much of the Internet is built out of free software.