WHEN Oscar Arias S'anchez, the President of Costa Rica, was a young professor of political science at the University of Costa Rica in the early 1970s, he heard about a graduate student whose undergraduate degree from Vassar College was not being accepted by the university. Knowing Vassar's reputation for academic excellence, Professor Arias telephoned the young woman, Margarita Penon Gongora, and said, as she recalls in an interview, ``Look, I know you are having problems getting your degree accepted, and I want to offer you any help that I can give you.''
It was an offer that was to change both of their lives. The two met, and in time their professional relationship blossomed into romance. In 1973 they were married, marking the beginning of a highly visible personal and political partnership.
President Arias has publicly praised his wife as ``an excellent adviser,'' a role Margarita Arias readily acknowledges.
``I have been very much integrated into the whole process from the beginning,'' says Mrs. Arias, a former high school teacher and the mother of the couple's 13-year-old daughter and nine-year-old son.
``I think Costa Ricans understand that although I have no formal power position, I do have a certain informal, moral duty. ... That makes my participation not controversial,'' she says.
Last month the Ariases traveled to Toronto, where both addressed representatives of philanthropic organizations. President Arias delivered the keynote address at the 40th annual conference of the Council on Foundations.
Mrs. Arias, as president of the new Arias Foundation for Peace and Human Progress, gave the opening speech at a meeting of Women and Foundations/Corporate Philanthropy.
She also met with leaders of 10 United States community foundations for advice on running the Arias Foundation, established last year with money from President Arias's 1987 Nobel Peace Prize.
As partner in her husband's peacemaking mission, she is working to extend the positive meaning of peace in specific ways. Her goal at the moment is to raise $2 million for an endowment, then use the income for programs to help women heads-of-households, children, and poor families.
``Peace is not only the absence of war,'' explains the serene and softspoken Mrs. Arias. ``There are other weapons as powerful as guns which destroy the most profound aspect of a people's soul - discrimination, hunger, lack of housing, illiteracy.
``All these deny the dignity of the human being in ways which are as lethal as the weapons of conventional war.''
One of those weapons, discrimination, looms particularly large, growing out of a long cultural tradition. The Latin American version of sexism, Mrs. Arias observes, is often portrayed in soap operas, best-selling books, and songs, and ``is lodged in the subconscious of men and, unfortunately, of many women as well.''
But, she says, ``Women are organizing to teach one another how sexism operates. Two of the national universities have begun women's programs, and many grass-roots women's groups have begun to study feminist theory.''
MRS. ARIAS also believes that the women's movement in Costa Rica has succeeded in getting many politicians to understand that public policy and sexism are tightly interwoven.
``So many aspects of [a woman's] life that have nothing to do with discrimination are actually quite relevant to the issue,'' she says. ``The availability of job training for single-parent households, the treatment of domestic violence, health benefits, pension plans, housing policies, income tax laws, where roads are built, where bus stops are placed, where schools are located - all focus on gender, even when it is not expressly mentioned.''
Gender does get specific mention in the nation's Constitution, which guarantees women equality. Equally important, a highly advanced family code, established in 1974, stipulates that a husband and wife have equal duties and equal rights. It provides equal recourse to divorce for men and women, and allows divorce by mutual consent, avoiding painful public court cases.
Yet the code says nothing about domestic violence, Mrs. Arias notes, and even punishes a woman who leaves her home in fear of being battered. It offers no protection to the partners and children of common-law marriages. It also fails to address the problems facing single mothers. New statistics show that half of all Costa Rican women who give birth are single, widowed, or divorced.
Last year the Arias administration appointed national committees to revise the family, criminal, and labor codes, with the aim of eliminating these inequities. A new law mandating full equality for women is also in Congress.
Through it, Mrs. Arias says, ``We seek to be guaranteed in practice the equality we are guaranteed in theory by our Constitution.''
Too often, she finds, administrative practices ``clearly discriminate against women when land is distributed among the poor. Women also find it harder to get loans, although studies show they pay their debts much more promptly than men.''
Still, Mrs. Arias sees signs of progress. A new Costa Rican law will require co-ownership of government housing programs, ``so that one partner cannot do anything with the house without the other.''
And in cases of a common-law marriage, the house must be registered in the woman's name in an effort to protect women and children from poverty.
Family issues are also receiving attention in a new report documenting the effects of war on children. The paper grew out of a Conference of Children Affected by Armed Violence in Central America.
In addition, the Center for the Development of Women and the Family, part of a government ministry, has been looking for ways to develop women's leadership.
Ninety-three percent of Costa Rican women are literate - a remarkably high rate in a country where half of the 2.8 million residents live in rural areas. And 25 percent of college-age women are enrolled in universities, compared with 29 percent of men.
COSTA RICANS also maintain a deep commitment to politics. ``Everyone gets involved in the process,'' Mrs. Arias says. ``Children are active and eloquent. They talk about it. They have songs and banners and stickers. And 90 percent of the population votes.''
Even so, since 1949, when women were given the right to vote, only 6.8 percent of elected congressional representatives have been women.
Increasing women's participation is essential, Mrs. Arias insists, saying:
``Our aim must be to break the vicious cycle in which things cannot get better for women until they can participate in policy making, while at the same time women cannot participate until things get better for them.
``When more women participate in policymaking at all levels of government, true equality between the sexes will have a better chance.''