Jaroslav Seifert, one of the ''grand old men'' of the Czechoslovak literary scene, has been awarded the 1984 Nobel Prize for Literature. The citation for the award, announced Thursday, said he had been chosen ''for his poetry which, endowed with freshness, sensuality, and rich inventiveness, presents a liberating image of the indomitable spirit of man.''
The words are apt for the way in which Mr. Seifert, who is 83 years old, has upheld his commitment to cultural freedom despite politics.
As a young man, he joined the Czechoslovak Communist Party and wrote for its publications. He was expelled in 1929 for challenging the increasingly subservient, pro-Moscow line of the party leadership at the time.
Because of his immense national stature, postwar communist governments could never totally silence or ignore him. The most they could do was to block republication of the magnificent lyrical poetry that had poured from his inner muse between the two world wars and until the Communist takeover of 1948.
In 1956, the year of Nikita Khrushchev's de-Stalinization, Seifert came out with an uncompromising condemnation of cultural policy under the still-Stalinist leadership headed by Antonin Novotny. Writers were, and had to be, the ''conscience of the people,'' he said.
He never again saw himself as a party political figure. But throughout his life he has identified with all that he regards as the best in ''progressive'' thought. His reputation was so enduring that in 1966 Novotny awarded him the title ''National Artist.''
In 1968, Seifert was one of the first to sign the ''2000 words'' manifesto with which writers and other intellectuals sought to strengthen the will of Alexander Dubcek in his fateful negotiations with the Soviets.
There is some doubt whether he signed the human rights charter of January 1977. But he clearly identified with its declarations.
His stature remains undiminished. This, it is felt, will deter the Prague regime from placing any obstacles in his way to receiving the prize. Whether he will be able to do so personally will depend on his health, his friends say.