When a man bears the weight of being poet, philosopher, hero, as well as the father of his country, as is Leopold Senghor of Senegal, some low-keyed days are in order. That was the tone and the pace yesterday of his first full day of a three-day, informal visit to Washington.

For most of the day, the mood of Senghor -- one of the leading intellectuals of Africa and a scholar credited with shaping the cultural philosophy of Negritude -- seemed to be one of rejuvenation and absorption. In the morning, he paused before the brooding Picasso canvas, "The Tragedy," at the East Building of the National Gallery of Art, and then participated in the solemn prayers of a high mass in French, and later, listened to his poetry and that of others at the Corcoran Gallery of Art.

As he left the National Gallery, Senghor said, punching the air for emphasis, "I'm, very happy I have remained a student and can draw inspiration from all of this." At the mass with the French community in Washington, he read from St. Paul and contributed to the collection.

Senghor's trip inaugurates Mayor Marion Barry's City Visit concept. Besides formalizing a "sister city" tie between Dakar and Washington, the visit marks the closing of the exhibition of contemporary Senegalese art at the Corcoran.

Among the 800 guests at the Corcoran were many scholars and artists who had received varying degrees of inspiration from Senghor. Pearl Bailey, the entertainer and Georgetown University junior minus three credits, received a book of poetry from Senghor See SENEGAL, B6, Col. 1> in 1977. "It was signed 'we have been watching you with love.' I was there at that time touring hospitals. I'm trying to go back in the summer because of those bonds," said Bailey.

During a meeting in 1970, Senghor encouraged Constance Hillyard, a Washington scholar, to use her knowledge of Arabis to translate some early Senegalese writings. "There's a large body of literature by black writers who happen to be Muslim and it is written in Arabic. Senghor was enthusiastic, but I'm sure he doesn't know what influence he had."

Among some of Senghor's best-known verses is the following from "New York," a poem which he subtitled "Jazz Orchestra; Solo Trumpet."

"Harlem Harlem! I have seen Harlem Harlem! A breeze green with corn

Springing from the pavements ploughed by the bare feet of Dan Dancers.

Crests and waves of silk and breasts of spearheads, ballets of lilies and fabulous masks

The mangoes of love roll from the low houses under the police horses' hooves."

Though Senghor is revered by many as a pivotal cultural figure of the century, not everyone endorses all his views. Acklyn Lynch, a professor at the University of Maryland, left the Corcoran before Senghor's arrival, protesting his imprisonment of a scholar, Cheikh Anta Diop. Herman Cohen, The U.S. ambassador to Senegal, said he didn't know of any such current case. "Senegal is free of political prisoners," said Cohen. "The opposition papers flourish. There's one that continually calls him the 'old man.'"

Dissent in Senegal, according to Marie Perinbam, a historian at the University of Maryland, is very prevalent among the upper class. "I was there in December, and the elite and intelligentsia are very critical but only in private," said Perinbam. "The feeling is that he is getting old, and in Africa to talk about the elders is impolite, discourteous and bad politics."

At the Corcoran the presence of an esteemed poet inspired the words of many of the afternoon's speakers. James Cheek, the president of Howard University, spoke of "the whispering winds of the Nile."

On the program were poets from Senghor's generation -- Sterling Brown and May Miller -- and contemporary voices -- Ethelbert Miller and Constance Carter. During the readings Senghor, seated with his wife, Camille, and Marion and Effi Barry, appeared contemplative. When Brown, the dean of Washington poets, read the famous "Strong Men," Senghor appeared to be mouthing the words.

At every stop yesterday, the humanistic vision of Senghor was evident. At the National Gallery, Senghor, whose remarks were translated by Senegalese ambassador Andre Coulbary, was effusive with compliments about the auditorium's design. "We hope some day you will come back and read your poems," said Charles Parkhurst, the gallery's assistant director. "How many seats do you have?" was the quick retort of the president. The Senegalese are building a museum for 26,000 pieces of art that do not now have permanent display, and Senghor said he was very impressed by the architecture of the National Gallery's new wing, which he called "astrasymmetrical parallelism."

Yet when Senghor took the microphone at the Corcoran, his first words were political, not cultural. "Let us take this occasion to salute the independence of Zimbabwe," he said. Before he leaves on Tuesday, Senghor is scheduled to have political discussions with Secretary of State Cyrus Vance and President Carter. Senegal is expected to send its athletes to the Moscow Olympics. (In 1976, Senegal did not support the African nations' boycott of the Montreal Olympics.) "I would hope if the great majority of African nations supported the boycott, Senghor would think again," said Richard Moose, assistant secretary of state for African affairs. "But I don't think President Carter will press him on it."

In the end, however, the message of art voided any thoughts of politics. Senghor spoke of solidarity. "We are all gathered here, and we are one," said Senghor. "The challenge is for us to prepare for a new cultural order."