Jose Maria Sison, the 47-year-old Communist leader released from prison today by Philippine President Corazon Aquino, planted the seeds of what is now a nationwide insurgency when he was a radical youth leader two decades ago.

Sison became widely known in activist student circles in the 1960s and '70s as a lecturer at the University of the Philippines, a poet and a revolutionary theoretician. Born into a middle-class family in the province of Ilocos Sur on the northern island of Luzon, he has a reputation for brilliance from his days of university organizing to his later years in leading the Communist Party of the Philippines.

A prolific writer, he also has a reputation for being dogmatic. In November 1964, he organized the youth wing of the Partido Komunista ng Pilipinas, a pro-Soviet Communist party founded in 1930. However, he soon became disillusioned with the party's leadership and embraced the Chinese Cultural Revolution led by Mao Tse-tung.

Three years later Sison and a group of supporters were expelled from the party when he wrote a lengthy critique of its failures and leadership. He was particularly critical of what he saw as the party's mistakes in the 1950s when its army, known as the Hukbalahap, was defeated in a premature drive to seize power. In his treatise, Sison called for the party to be rebuilt.

On Dec. 26, 1968, Mao's 75th birthday, Sison and 10 young radical followers held a "congress of reestablishment" in a village in the province of Pangasinan in Luzon and founded a new party, the Communist Party of the Philippines. Sison became its first chairman.

Shortly afterward, Sison and his followers linked up with a remnant of the old Huk insurgent movement commanded by Bernabe Buscayno, known as Commander Dante, who was also released today. Buscayno had broken with his Huk commanders, who had abandoned revolution and turned to banditry and criminal activities that included running protection rackets in the town of Angeles outside Clark Air Base, the largest U.S. Air Force base outside the United States.

Sison and Buscayno formally joined forces on March 29, 1969, with the founding of the New People's Army, the armed wing of the Communist Party of the Philippines. Dedicated to waging a "protracted people's war," the guerrillas started out with 35 old rifles and handguns shared by about 60 rebels, according to Sison.

Using the pseudonym Amado Guerrero, Sison set out the strategy and goals of the revolutionary movement in a series of underground works published in the early 1970s. In "Specific Characteristics of Our People's War," he expressed hope that a revolution would make "a worthwhile contribution to the advancement of Marxism-Leninism and the world proletarian revolution so that in the end mankind will be freed from the scourge of imperialism and enter the era of communism."

The treatise described two main weapons of the Communist Party: armed struggle and the national united front, which were compared to "the spear and the shield." However, it made clear that "armed struggle is specifically a weapon for carrying out the central task of the revolution, which is the destruction and overthrow of the enemy rule and the seizure of political power."

After Buscayno and Sison were captured in 1976 and 1977 respectively in Luzon, the party shifted away from a Maoist orientation to a more pragmatic approach toward revolution in this archipelago of 7,100 islands. Under a new chairman, Rodolfo Salas, a former engineering student also known as Commander Bilog, the party and its army have grown rapidly. The party now claims to have about 30,000 members and about 30,000 "full-time and part-time" guerrilla fighters operating nationwide.

A staff report to the U.S. Senate Select Committee on Intelligence last November said the Communist Party "controls or is contesting control of settlements inhabited by at least 10 million people."

While Sison has issued statements from prison through his wife and continues to be revered by Communists as the founder of the party, the extent of his current influence is unclear. But he is believed to remain committed to the overthrow of the country's present system, which he has said is characterized by "U.S. imperialism, feudalism and bureaucrat capitalism."