Louis Lapham believes he has resolved what's been troubling him. He has worried about the burden of contemporary information shoveled onto our shoulders by any number of journals and magazines.
''Given too much to read, (people) tend to read as little of it as possible, '' he wrote in his ''Easy Chair'' column in the January Harper's. Magazines pile up unread, intimidating in their inventories of facts and attitudes.
Lapham returned as editor in chief of Harper's magazine last September and will implement in March what he was not permitted to do before he quit the magazine in August 1981.''How many publications are there that we should read every month?'' he asks when the Monitor engages him in conversation. It's a rhetorical question because he's ready to answer it with another query: ''50?''
He enumerates the components of a pile of one month's magazines, a stack tall enough to please only the Collier brothers: four copies of the New Yorker, four each of Time and Newsweek, other purveyors of cultural and political commentary such as New York Review of Books, New Republic, Commentary, The Nation, and more , including Harper's.
Lapham says, ''Most of these magazines are competing for the same audience, and to do so we all use the same writers. Once a writer gets to be a V. S. Naipaul, he can write for any of us. There's a universe of maybe a million people to reach, and the problem is to make the magazines appealing to more than a small group of readers. We can't say our magazine has the best writing in it. Since the same people are writing for all of them, that's nonsense.''
Thoughts such as these have goaded Lapham from tradition to innovation. Beginning with the March issue, Harper's will no longer resemble the kind of magazine it has been for decades. No longer will it consist of a battery of essays and reports presenting, analyzing, and speculating on cultural and political developments in the world.
''The magazine will not be a formula,'' says Lapham, and when he voices it, this customarily pejorative word sounds as though it embodies hints of Archimedes's ''Eureka!''
Harper's is being totally redesigned - new logo, new look, new layout - but it is the contents itself that indicates the major overhaul in sight. Starting with the March issue, you will find the following filling its pages.
The Harper's ''Index.'' This will be a single page of statistics, nothing but statistics - the total number of people in all the armed forces in the world; the number of ounces of cocaine seized by United States federal agents; the number of politicians indicted in Massachusetts; the number of patents applied for; the size of US trade with Syria.
Next will come 20 pages of extracts from newspapers, magazines, journals, press releases, and other providers of thought and data from around the world. Juxtaposition will be important - Joanna Carson's living expenses alongside Solidarity's budget; several paragraphs from Renata Adler's new novel ''Pitch Dark,'' and a portion of an interview with a Playboy bunny. ''The pieces will be picked for reasons of insight. They'll usually be things that most people would never see, and they will, among other things, provide a sense of values,'' says Lapham.
Also planned is an annotation of a contemporary document, which, in March, will be a massive hospital bill incurred by a woman patient who died without the cause of death ever having been determined. Later issues may annotate the Reagan administration's dictum restricting publication by government officials, or a telephone bill, a script of television's ''Dynasty,'' or the hallowed 1040 tax form. ''It's not supposed to be the device of the month,'' Lapham remarks. The intent is to explicate the text of a document of relevance.
A major feature will be the monthly symposium dealing with a topical subject. In March the question is ''What Is America For?'' The respondents to these puzzles will be drawn from lesser known figures and from such writers and thinkers as Robert Stone, Martin Marty, Michael Harrington, and Louis L'Amour.
The Harper's reader will also find a cultural piece considering the world of books, or that of theater, or that of opera, or whatever. There will be a report , such as V.S. Naipaul's analysis of events in Grenada. The book review will be of a classic. In March John Updike will review Sherwood Anderson's ''Winesburg, Ohio.''
When it is suggested to Lapham that Harper's will now read like a high-class Book of Lists or People's Almanac, he grins and says, ''Maybe more like a high-class Reader's Digest.''
However, what Harper's will continue to be, maintains its editor in chief, is ''a magazine of political and literary opinion, which it's been since 1960.''
Lapham will reprint articles, and he will run original pieces. Fiction will be welcomed when he encounters fiction he considers worthwhile. Poetry too. ''My obligation is not to New York wise guys,'' he says. ''It's to the readers out there, and what I want to do is take all kinds of material and give it some coherence.''
The circulation at Harper's is at present around the 140,000 mark. It has not been on the increase in recent years, but Lapham expects that to change.