MATIYARI, India— More often than in the past, there comes these days what one Government official calls ''a very philosophical moment'' for the couples who live in villages like this one in northern India when they decide not to have more children. The moment signifies to some who face it a radical break with centuries-old attitudes on life and birth.

For Phoolmati, a 35-year-old woman who works in the rice fields every day to feed her three sons and two daughters, the decision to undergo sterilization was matter-of-fact.

She decided, she later told a visitor, that if she had any more children she would not be able to properly feed, clothe and educate them.

Such thoughts must compete with more powerful sentiments that push in the opposite direction and still usually prevail. New Ideas Catch On

But now, say those who are working in the countryside in a new push for birth control, the new ideas are beginning to catch on in India, the world's second most populous country. As a result, they said, family planning, in disrepute for years after the forced sterilizations of Prime Minister Indira Gandhi's emergency period in the mid- 1970's, is again becoming accepted.

The Government is hopeful that by the turn of the century India will attain the two-child family norm that will enable its population eventually to stabilize. To achieve that goal, it is estimated, 60 percent of all married couples will have to be ''effectively protected'' against childbearing by then. About 25 percent are now considered to be so protected, up from about 10 percent in 1971. An intermediate target has been set of 36 percent by 1985.

If the goals are achieved, the Government predicts, India's population will grow from an estimated 735 million at present to 950 million in the year 2000. At that point, it hopes, the population will begin to stabilize automatically, reaching a more-or-less permanent plateau of about 1.2 billion by the mid- 21st century.

Education, the affluence of a rising middle class and spreading urbanization are bringing with them a natural drop in the birth rate in the cities, where the two- or three-child family is becoming the norm. Real Test Is in Villages

But the real test will come in the villages of India's countryside, where three-quarters of the people live, and in particular in the Gangetic Plain, where this village of 1,600 people is situated.

The plain, home to about a third of the nation's people, is not only where the most serious effects of the population explosion are felt but also where old ideas remain most entrenched.

In Matiyari, the numbers reflect the resistance posed by tradition. Family- planning and health aides who work in the village say that 278 couples here are of childbearing age and therefore ''eligible'' for free Government birth-control services. Above the State's Average

Of these, 60 - or about 22 percent - are now practicing some form of birth control, including sterilization, regarded as effective.

Matiyari's 22 percent is below the national average of 25 percent and below that of large cities, but is well above the estimated overall figure of 12 percent for Uttar Pradesh, the state in which it is situated.

A major problem is that couples typically choose to stop having children after having three, four or more, not the officially promoted ideal of two. Family-planning workers say that the great majority of village women would rather stop sooner than later, but that several factors deter them.

Some women seem at a loss on how to proceed. Family-planning workers have a lot of territory to cover and it can be a long time before a woman gets the advice and help she needs.

Further, Indian villagers have long believed that many children are economically necessary, both to provide enough hands to work the fields and to be sure that parents will be taken care of in their old age. High infant mortality rates in the past have also prompted many families to have more children in case some die, and because male children are regarded as an asset and females a liability, many couples keep trying to produce sons.

Religion also plays a major part. ''Whatever happens, good or bad, is in the hands of God,'' said a Hindu woman in Matiyari who has four children and has resisted appeals that she become sterilized. This conviction is said to be even more prevalent among Moslems, whose families tend to be larger.

Some Resentment Remains

There remains also some feeling of resentment from 1976, during Mrs. Gandhi's emergency, when the Indian Government for the first and only time resorted to compulsory sterilization. Like many other medical officials, Dr. R. S. Pundir, the deputy chief medical officer for the district in which Matiyari is situated, remembers that time.

''The police literally dragged people in from the fields to the vasectomy table,'' he said.

As a result there were more than six million sterilizations that year, three times the number of any previous year.

Another result was that the public outrage generated by the program was so great as to become a factor in Mrs. Gandhi's electoral defeat in 1977. The new Government, in reaction, shunned family planning, and sterilizations dropped to 188,000 in 1977-78. Figures Tell the Story

The drop locally is reflected in figures posted in the Chinhat Government health center, which has jurisdiction over Matiyari.

In the year 1976-77, 704 sterilizations were performed at the center. In 1977- 78, one was performed, and in 1978-79, 11. The number jumped again in the next two years to 52 a year, then to 242 in 1981-82 and to 341 last year.

Family-planning workers say they are cautiously hopeful that this time the growth will take place on a solid base of acceptance, and that the base will continue to grow.

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