Overlooking Revolution Square at the foot of this mountainside city are two enormous portraits of Marx and Lenin, the new patron saints of this ancient African empire now deep in revolution and looking to the East for inspiration.

Pictures of Marx, Lenin and Castro adorn the walls of government offices, public places, schools and private homes where once hung the stern face of emperor Haile Selassie, deposed and imprisoned in the first months of the revolution 4 1/2 years ago.

The bookstores and corner kiosks are filled with the collected works of all the chief communist theoreticians, selling for 35 cents to a dollar per volume.

Giant billboards show factory workers or peasants breaking their chains in the style of socialist realism -- leaning forward with one leg and one arm stretching skyward.

Whenever a parade is held, half the flags are red and bear the communist emblem of a hammer and sickle with a star above it. The other half are still the green, yellow and red of Ethiopia. But they seem lost in the sea of red banners, bandanas and bunting.

To all outward appearances, Ethiopia is well on the way to becoming a communist state. Its new military leader, Lt. Col. Mengistu Haile-Mariam, has become the first african leader to state bluntly that this is his government's aim.

"Our goal is socialism and communism," he said in a speech Sept. 12 marking the fourth anniversary of the late emperor's downfall. At his side sat Cuban President Fidel Castro, the firs communist leader to come to Mengistu's aid and to understand the potential for the Ethiopian revolution to evolve like Cuba's own.

But is Ethiopia, a once feudal empire with a 2,000-year-old independent history, really going communist? What does this mean, anyway, in an African country with such a strong nationalist and Coptic Christian tradition and a peasant-based society long impervious or violently hostile to attempts by various foreign powers to influence it?

Ethiopians as well as Westerners and Easterners are asking these questions with no certain answers and a keen awareness that past Soviet attempts to make communists out of Arabs and Africans have ended in a series of disasters -- Egypt, Sudan, Guinea and Somalia.

Even $1 billion worth of Soviet arms and eight years of Marxist indoctrination did not supplant antionalism and Islam as the driving forces in neighboring Somalia. Can the Soviets and Cubans override similar forces here?

Some longtime Western residents dismiss the blitz of Marxist propaganda as an Ethiopian ploy to gain Soviet backing in hot pursuit of strictly nationalist interests. In their view, Ethiopia found itself threatened in 1977 with disintegration as Eritrean and Somali separatists as well as oldregime loyalists took over almost half the country.

In this view, the new military government, lacking U.s/. support had to turn to the Soviets and Cubans for massive military assistance.

Ethiopia, remarked one oldtimer, "is neither pro-East nor pro-West. The present propaganda is all facade. They are paying for their Soviet arms with words.But behind the scenes they are not communist. They are just Ethiopians."

Whether this is a naive view or profound insight only time will verify. For the moment, even the country's new true believers say Ethiopia has a long way to go before it is really a socialist, let alone a communist state.

According to the new regime's Marxist ideologists, Ethiopia is still at the stage of a "national democratic revolution" similar to what China went through just before and after the Communists there seized power in 1949.

"At this point, we are only a socialist-oriented revolution," said the director of the revolution's ideological school here. It is in charge of indoctrinating top officials of the government, army and labor union with the Marxist-Leninist creed.

So far, 8,000 Ethiopians have passed through the one- or three-month program at a former home of the royal family.

The courses include study of the writings of Marx, Lenin and Engels, the application of scientific socialism, the experience of successful socialist countries and of some unsuccessful ones, like Chile, and the history of the three Communist Internationals as well as techniques of building a communist party.

The school gives no attention to other socialist experiences in Africa. The result is that Ethiopian ideologists think, analyze and talk as if Ethiopia were Russia or China just after the communist parties there took power.

The military government hopes that from the school's graduates cadres will emerge to organize and staff the party for the working class that is supposed eventually to lead the revolution. Right now, the army is still in charge, and many otusiders here doubt whether it will ever hand over power to a civilian-dominated party.

The havy dose of Marxism-Leninism has spread from the capital deep into the countryside. The cubbyhole bookstore in Goba, a dusty market town in southern Ethiopia, now carries nothing but Marxist and Soviet literature, aside from one Regis Debray book on revolution in Latin America.

All the headquarters of the All-Ethiopian Peasants' Association in Debre Zeit, 25 miles south of Addis Ababa, a chart of the Soviet system of government is plastered on the wall for reasons left unclear.

Whether this concentrated attempt to indocrinate Ethiopians with a communist national and international outlook is penetrating below the surface is difficult to judge.

Many students, intellectuals and young civil servants seem taken by it and talk in the Marxist lingo with ease if not always with complete understanding. But the older, Westerneducated generation, mamy technocrats, traders, and businessmen remain exceedingly skeptical.

Meanwhile, church sources report increasing attendance at both mosques and churches -- Protestant, Catholic and Coptic -- and point to this as evidence that Ethiopian society is not digesting the new Marxist religion.

The great silent majority are the peasants -- 90 percent of Ethiopia's 30 million population. They have been organized into associations, armed to defend their considerable gains from the revolution and enrolled by the tens of thousands into amilitia to go fight Eritrean and Somali separatists.

Their revolutionary zeal and nationalistic spirit have been proven on the battlefield. But the peasants have yet to evidence any clear appreciation of Marxism, In fact, their "individualism" and "petty bourgeois tendencies" are being castigated daily by Col. Mengistu as a major stumbling block on the road to socialism.

Some Ethiopians feel that whether Ethiopia will ultimately go communist depends heavily on the Eastern bloc's ability to meet the critical need for massive economic and financial assistance.

This, they point out, is precisely where the Soviets and their allies have fallen down in the past in Africa and may again prove the Achilles' heel of their offensive.