A year ago here in Egypt, I tried to look directly at the opposition to President Anwar Sadat. I talked to Islamic students, Moslem brothers, Arabic radicals, Nasserites, communists, independents and opportunists. I came to the conclusion that the opposition was too disparate and disconnected to be evaluated effectively by an outsider.

This time, in Cairo, I have tried to consult Egyptians who have to make it their business to gauge the strength of the opposition to Sadat. To that end, I talked to three different men -- an important professional writer, a former official of high rank, and a left-wing journalist.

The writer told me a story about a visit he paid to Tehran in 1975. He went to visit a leading opponent of the shah's regime, Karim Sanjabi. Sanjabi refused to talk in his apartment for fear that the conversation would be bugged. When they were outside in the streets, he told the writer:

"Our opposition to the shah is disorganized and demoralized. We have been totally infiltrated by the police. We have lost all our following."

"If that's all you have to tell me," the writer inquired, "why couldn't you tell me that in the apartment?" "Because," Sanjabi replied, "I didn't want the shah's police to know just how weak we are."

"The moral of that story," the writer told me, "is that in Third World politics, nobody can ever gauge the strength of an opposition. Not even the opposition itself." In underdeveloped countries, where there is no legal opposition, those who are opposed inevitably go underground. Their strength becomes apparent only when they emerge. In Egypt that is not yet."

The former high official told me that two of the ranking members of the government -- Prime Minister Mustafa Khalil and Deputy Foregin Minister Butros Ghalli -- were bitterly opposed to Sadat on the matter of giving the shah of Iran asylum in Egypt. He thought Butros Ghalli might have to resign at any moment.

He also showed me a foreign intelligence report on dissidents in the air corps. The report recounted, with a wealth of detail, an engagement between Egyptian planes and Ethiopian planes piloted by Cubans over the Sudan. The Cubans, flying the latest Soviet models, had blown the Egyptian, flying older Russian planes, out of the skies. As a result, the Egyptians were now pressing the United States for more sophisticated aircraft. In addition, a section of the air force had tried to mutiny against the regime. A coup d'etat had been only narrowly averted.

I was in no position to check the second report. The first report -- about Khalil and Butros Ghalli -- I could and did check. It turned out to be false.

The left-wing journalist told me a series of unconnected stories. One involved a call-girl network run by wives of distinguished Egyptian diplomats. iThe ring had been discovered by a high official who had used the information to force his rivals from office.

Another story centered around the refusal of various people in Cairo to accept normalization of relations with the Israelis. Society women would not receive the Israeli ambassador. Various journalists had complained to President Sadat about his order to treat the Israelis well in the press.

He also told tales about groups of judges and lawyers who refused to accept the president's project for a law that would muffle criticism of the regime and its Israeli policy. He said that a group of 40 of the most distinguished Egyptians had signed a petition to the president affirming their opposition to his policies.

Finally, he was full of information about tensions between the increasingly Islamic student body, and the Christian community, or Copts. He told me that the supposed incidents at Assiut and Alexandria protesting asylum for the shah had been fights between the two communities. He said the Moslems were increasingly strident in proclaiming their beliefs. As a result, the Coptic community was increasingly on the defensive. The Coptic pope, Chenouda III, had absented himself from Cairo at Easter time to protest against the government policy of coddling the Islamic opposition.

I come away from all this about where I began. No doubt opposition to Sadat exists. But it is submerged and dispersed. As long as Sadat is in office, we will probably never know its strength. After which, the question will be academic.