Mexico seen through the eyes and lives of its people, rich and poor

She is a woman of impeccable gentility. As she serves tea to a visiting reporter, she chats readily about her father, a dirt-poor Indian boy who rose to national prominence as violinist, conductor, and composer. Her brother served in ministry posts in the government and as ambassador to the United States.

Everything about this small woman with dark hair, smoky eyes, and quick, decisive movements - including her home in an aristocratic section of Mexico City - bespeaks dignity and pride.

So you will excuse Dolores Carillo-Flores when she points out, quite simply, that her family belongs to ''the Mexican aristocracy of intellectuals.''

She seems constantly aware of her separateness from the world around her and her aloofness from the problems of this society - a society increasingly important because of its $90 billion foreign debt, its indocumentados scurrying over the border, and its linchpin status between the United States and insurrection-riddled Central America.

In that respect, she embodies both the fragmentation and insularity of Mexican society - conditions long felt in the lives of Mexicans but only dimly understood in other countries increasingly affected by the Mexican situation.

Traveling through even a small slice of Mexico, talking to the people at all levels of society, one lesson is driven home again and again: that Mexico is less a single country than many countries speaking many dialects, emerging from many different cultures, yet bound together by a common economic reality and a single government that must deal with that reality.

To Santiago Levy, a Mexican economist on a temporary teaching assignment in the US at Boston University, both the fragmented society and the economic reality present a grim picture. ''With the labor force growing at 31/2 percent a year, and the economy growing at only 1 percent,'' Mr. Levy points out, the country has little hope of addressing its chronic ''underemployment'' problems.

Levy sees some hope in the stringent fiscal measures being taken by the De la Madrid government. But Latin American specialists contacted after returning from Mexico paint a picture of a nation mired in centuries-old social structures. They say Mexico is a captive of deep, pervasive social forces.

The stratified segments of Mexico ''know their place in the society,'' says Latin American specialist Susan Eckstein, author of ''The Poverty of Revolution: The State and Urban Poor in Mexico.'' Mexico is a ''society that historically has been unable to pull itself together centripetally,'' adds John Womack Jr., a Harvard professor specializing in Mexico. And he points out that the pluralism of the country has helped to keep it from changing much with the times.

The only thing that hasn't changed in Senorita Carillo-Flores's life behind stucco walls is everything: the portraits on the walls, her father's collection of pianos, her life among the gardens and winding staircases, the servant girls chattering in another part of the house.

At the moment, she is apologizing that one of these girls ''has not yet learned how to serve properly. I brought her up from a village in the south. . . . She has her own room, all her meals, and a day off every week, although she doesn't really know anyone here to visit.

''I don't think she has any reason to complain,'' she adds.

Yet this errant mestizo girl, with her wholesome beauty and rough-hewn ways, probably came from a world not much different from the one Senorita Carillo-Flores's father was born into 109 years ago.

Her brothers, sisters, and neighbors are either out of work, eking out a minimal subsistence, long fled across the border to the United States, or among the very fortunate who have jobs in Mexico. Coming here to this house, she must adapt to a life style almost as different as that encountered by her indocumentado relatives and friends in the United States.

In the mountainous country between San Miguel Allende and Guanajuato is a world similar to the one she came from. Back from the main highway, on a dirt road that snakes through dry, ungenerous country, Marguerito lives with his family in a sun-bleached adobe-style one-room house.

The trickle of a stream that passes just outside his land does little to help him raise crops. So when you ask if he can grow anything on his land, he grins and points to the dead stalks in the parched earth. Leaning beside a reporter's car, wearing faded jeans torn at the knee, old open sandals, and a straw hat, he squints in the sun and says that life in Mexico gets harder year by year but that it has always been hard. He knows little about the government in Mexico City, little about the economy of the country, less about the world outside Mexico.

Conversations with a dozen campesinos around the central region of Mexico all bear the same aura of heavy burden and almost total resignation.

The distances, geographic and social, between such people and Senorita Carillo-Flores are said to be as wide as those between the wealthy and the poor throughout Mexico's violent history. They yawn like the endless stretches of mountains and plains. Even the indigenous rulers never really bridged them. ''Possessed of a powerful apparatus for conquest,'' writes Eric Wolf in ''Sons of the Shaking Earth,'' his brilliant anthropological study of the region, ''they did not overcome the essentially insular character of Middle American society.''

Susan Eckstein carries the point into the present: ''There is this sense of hierarchy and deference in Mexico.'' Even during the violent upheaval of the revolution, she says, ''getting better jobs or higher wages was not something the peasants felt they could reasonably expect.'' And not only the peasants. Conversations with Mexicans in almost every walk of life seem tinged with a pervasive sense of resignation, as if the currents of daily life are steered by powers way beyond one's reach.

''Why don't people change things?'' offers a Monterrey businessman as he rocks uncomfortably on a train destined for Chihuahua. ''Because they are too lazy, too afraid. The government is too powerful.''

This attitude is apparently more than a social accident. ''One of the pillars of the regime is public apathy,'' comments a Massachusetts Institute of Technology professor, Peter Smith, the author of ''Labyrinths of Power,'' a study of Latin American power structures. ''That's a deliberate tactic. They don't want the population to be mobilized.''

Perhaps the world here is too far-flung and disparate ever to mobilize itself. You travel a vast socioeconomic distance from a cul-de-sac slum in Mexico City, with a small, open sewer running through it, to the wind-swept mountain dwellings two hours away by car along Mil Cumbres (the road called ''Thousand Peaks''), and on to a suburban park in prosperous Morelia another two hours down the road.

It's easy to look at the barriers flung up by these distances and despair, as many observers do. But there are indications that the most stultifying effects of Mexico's economic woes are being addressed - even though the immediate prospect is for more struggle and privation.

''Next year will be a hard year,'' predicts economist Levy at Boston University. ''Things will not improve much.'' But he quickly adds that there are promising signs at the top of Mexican government: ''The country is now being run by competent people. The results (of the government's austerity program) are beyond any expectations. They have beat dismal forecasts. They are making adjustments in wage payments.'' These signs give comfort to International Monetary Fund bankers, who have put heavy pressure on Mexico's leadership.

And you can even see signs, in the midst of the widespread hardships the measures have imposed on the average Mexican, that they are registering, however faintly, in the villages.

On a twisting side street in San Miguel Allende, for instance. A small man makes his way through the early-morning sun, carrying a bundle of brooms on his back. Stopping to talk to a reporter, he smiles ingenuously with his wide eyes and childlike face:

''Things are better for me, now, senor,'' he says in Spanish, drawing out his words in that Mexican way that invites longer conversation. ''Last year there was no work. This year, they are hiring at the rancho. Things are very much more expensive. But, you see, I am selling brooms on my day off. And we get by.''

He is 20 years old. He cannot read. And he says that he really doesn't know why things have improved for him, any more than he understood why they went downhill in recent years. When you mention the actions of the government in Mexico City, he looks at you quizzically, as if to say:

''That is a totally different world.''