When you stop to think about the creation of Lear's, the much-hyped new magazine for women over 40, you cannot help being amazed that no one has thought of this before. It's a natural. The entire culture of women's magazines has held up youth, baby-faced beanpole vacant-eyed youth, as the ideal of beauty. Now, a magazine that creates a new, or at least another, ideal. The gimmicky mantra at Lear's is "the woman who wasn't born yesterday."

Frances Lear -- the ex-wife of entertainment impresario Norman Lear -- is so sure her invention will endure that, along with "Editor-in-Chief," she is already calling herself "Founder" on the masthead. That takes chutzpah.

The demographics for such a magazine are certainly promising, though not as promising as Lear seems to think. "In 1987," she writes in the March/April debut, "there were three women over 40 for every two in 1986" -- a statement of such thunderous improbability that one has to wonder about the editor's grip on reality.

Lear's outlook can be understood immediately through any one of the sentences in her opening message. Here's one at random: "But you, unique in history, are offered even more: new routes, the joy of being recognized for doing something well, while bearing in mind that unexpressed creativity turns inward and does harm."

Better to ignore the incantatory claptrap and look at the magazine. The sensation generated by page after page of exotic and attractive and sexy women who bear some resemblance to the kind of people we call adults is strange, as surely it shouldn't be, but it is quickly wonderful, too.

For text, Lear's offers lots of packaged practical advice, as well as exemplary tales of women who didn't surrender to chronology and their own low self-expectations. There's also a durable Doris Lessing story and a charming Anne Bernays explanation of how she and her husband have stayed married for 34 years.

If you want to subscribe, sight unseen, send $15 for six bimonthly issues to Lear's, P.O. Box 51233, Boulder, Colo. 80321-1233.

Citizen Jane

At the other end of the age spectrum -- for women who are, effortlessly, baby-faced beanpoles, the 14-to-19 age group -- there's a new magazine called Sassy. Sired by Fairfax, the Australian publishing company that recently bought and remade Ms. magazine, it's being edited by a 24-year-old American woman named Jane Pratt.

The first issue (March) is a lively piece of work. Among the usual service stuff and hunk profiles are some attention-getting stories, like tips on losing your virginity and how to cope with a friend's suicide.

Pratt certainly doesn't lack for pep or confidence. Her editorial presence and her interjections are on virtually every page. Here she pops up in Karen Catchpole's story on virginity: "After hearing dozens of people recount the details of their first time {Tough assignment, Karen -- Jane}, it seems more likely ..." Two features actually begin with Jane having the idea for the story or giving the assignment. A movie review contains Jane's views as well as the writer's. What have we got here, a cult of personality? Jane Pratt, meet Frances Lear.

To subscribe, you'll probably just want to get on the phone to Jane in New York. But if you want to be formal about it, send $13.98 to Sassy at P.O. Box 50093, Boulder, Colo. 80321-0093 for 12 monthly issues.

Breaking Silence

"We did not survive the gas chambers and crematoria so that we could become the oppressors of Gaza," writes Michael Lerner, editor of Tikkun, in a March editorial. "The Israeli politicians who have led us into this morass are desecrating the legacy of Jewish history."

Lerner goes on to list the reasons why, "from a strictly self-interested position, the occupation is stupid." Among them is a future for Israel of "hard times based not simply on lies and distortions of anti-Semites, but on the justified indignation of many people who see the Jewish state embodying a viciousness and moral callousness that they would find repugnant anywhere."

The solution, for Lerner, is a "demilitarized and politically neutral Palestinian state ... on the West Bank and Gaza" whose peaceful intentions and protection from attack would be "guaranteed" by the United States and the Soviet Union. But his real purpose here is to raise the consciousness, and break the silence, of American Jews.

For other voices and other solutions, the March issue of World Press Review provides a sampling in a cover package devoted to the "Rage Against Israel."

The Woozy Workplace

If you suffer from headaches, dry skin, itchy eyes or drowsiness when you're at work, it's not necessarily because of your boss. It could be the office itself. The Washingtonian's Randy Rieland has investigated what's known as "sick-building syndrome" -- indoor pollution caused by bacteria and chemicals in office air and water systems -- and prepared a report for the March issue on what may be ailing you from 9 to 5. Washington has some of the sickest buildings in the country, apparently, and Columbia Plaza, the Hubert Humphrey Building and the Forrestal Building are high on the incurable list.