Ivan Illich, 76, a noted sociologist who protested the institutionalization of learning and religion, died Dec. 2 at his home in Bremen, Germany. The cause of death was not reported.

Dr. Illich, who was best known for his 1971 publication "Deschooling Society," had lectured in sociology at the University of Bremen for the past decade.

Regarded as both a crank and a visionary, he railed against modern technology, the education system and standardized health care. He maintained that modern technology was oppressive, claiming, for example, that automobiles enslaved society and that bicycles were a faster way to travel.

Dr. Illich, who was born in Vienna, Austria, was forced to leave school in 1941 under Nazi race laws because of his mother's Jewish ancestry. He went to Italy and studied in Florence and at Rome's Gregorian University before returning to Austria and obtaining a doctorate in history from the University of Salzburg.

He entered the Roman Catholic priesthood and, from 1951 to 1956, served in New York as an assistant pastor, championing the cause of Puerto Rican immigrants. From 1956 until 1960, he was the deputy rector of the Catholic University of Puerto Rico.

He became a familiar name in religious and educational circles after he founded a training center in Cuernavaca, Mexico, in 1961. Part language program, part think tank, the Intercultural Center of Documentation prepared missionaries to work in Mexico and Latin America and attracted priests, nuns and lay Catholics.

At the time he opened the center, Dr. Illich was a Catholic monsignor, but from the first he challenged his students' assumptions about Western superiority and religious patriarchy, which soon embroiled him in ecclesiastical controversy. His view that the Catholic Church should dissolve its bureaucracy did not help his standing with the Vatican.

In 1968, he was called to Rome to explain but refused to answer questions. Thousands of dollars in church funds were withdrawn from his center, and he severed ties between the center and religious institutions. A year later he resigned from the priesthood. By then he had chosen the social causes that occupied him for the rest of his life.

Reflecting his discomfort with organized religion, he argued that school made people dumb, and the legal system, rather than providing people with solutions, heightened their frustration. He argued that even science was being strangled by institutionalization.

Once a Roman Catholic priest, Illich founded a training center in Cuernavaca, Mexico, in 1961 to prepare missionaries to work in Mexico and Latin America.