"Can't I come visit sometime, maybe spend a night or two?" asked Sen. Mark Hatfield of the guest in his office. The Republican from Oregon, a reflective politician given to intellectual curiosity, had been working at full bore on the last afternoon of Senate business before the August recess. Wearied, he was taking a break by having a conversation with Jean Vanier, whom the senator has long admired.

Since 1964, Vanier, a Canadian- born philosopher and writer, has been credited by people such as Hatfield with having done more than anyone to embrace the mentally handicapped. The breadth of Vanier's achievement is not widely known, but in time he will surely be honored as one of the world's genuine healers.

Twenty-one years ago, Vanier, settling in a village an hour north of Paris, bought a cottage and took into his home two mentally handicapped adults who had been living in a local asylum. About 400 mentally handicapped men and women are now cared for by Vanier in the village of Trosly. Worldwide -- in 18 countries that include the United States, India, Haiti, Ireland, Australia, Spain and Honduras -- Vanier oversees a network of more than 200 homes in which the handicapped and nonhandicapped live together as families.

In 1964, Vanier placed over the door of his Trosly cottage a wooden signboard carved with the word "l'Arche" -- French for the ark, the biblical symbol of refuge and deliverance.

When Hatfield asked if he could visit a l'Arche community, he did not know that one of them was less than three miles from the Capitol -- in the Adams- Morgan area of Washington. The July 16 Congressional Record has an entry on the community, put there by Rep. Dante Fascell (D-Fla.) to mark the first year of service. One of Fascell's assistants, Ivo Spalatin, the staff director of the House subcommittee on arms control, is president of the community.

Vanier told Hatfield that he was welcome anytime to any l'Arche household and to stay as long he wished. The senator said he would make arrangements to spend a few days in September at the Washington house. What he will find there has been written about in eight books by Vanier, each of them a call to conscience and self-giving. The writing emits a rare kind of intellectual integrity. Vanier's learnedness -- he has a doctorate in philosophy -- is no mere magnification of theories which often passes for wisdom in the world of position papers and reports.

When he came to live in 1964 with those "who had been wounded in their minds," Vanier recalls that he "discovered the two worlds that exist side by side: the world of the 'normal' people who seek social status and are motivated by ambitions of efficiency and riches, and the 'abnormal' world of the despised, the handicapped, the 'not-adapted ones.'

Vanier, who continues to live in Trosly, is frequently critical of efficiency. We are being "drowned in a mounting tide of efficiency." His childhood, when it appeared as if his military- school education was leading him to a career in the Royal Canadian Navy, was "geared to efficiency." What evolves from Vanier's thinking is that the mentally handicapped -- supposedly the inefficient ones -- are "a source of life and truth, if we welcome them (and) enter communion with them and put ourselves at their service."

For many, merely putting themselves at forced proximity to the mentally handicapped is too much. The courts go both ways in cases involving discrimination. In July the Surpreme Court struck down a Cleburne, Texas, ordinance that kept out a group home for the mentally handicapped. But last September, the Virginia Supreme Court sided with a group of Chesterfield County residents who filed suit to prevent construction of two homes. The sites would have housed four mentally handicapped adults and a full- time counselor.

Vanier has been through these vicious anyplace-but-here struggles. "People with mental handicaps are an enigma for our society," he has written. "In today's society, which is so organized and structured, they are seen as an economic burden. Their presence disturbs people. Very often people look down upon l'Arche as if we are completely mad. I realize this more and more. We at l'Arche consider those whom society devalues as valuable and capable of awakening what is most precious in a human being -- the heart, generosity, the dynamism of love."

In his conversation with Hatfield, Vanier, whose father served eight years as the governor general of Canada, used the metaphor of the ladder of success. We teach ourselves the ways of climbing it, he said, as if the top rung is where happiness is. Vanier argues the opposite: by descending the ladder and by going among those who are at the bottom -- the poorest, the sickest -- a chance for "true community" is found.

The senator appeared to understand. Should he spend some time with the l'Arche community near his office, it is likely he will understand more.