Socrates, known for his elegant style on the field and his deep involvement with Brazilian politics, acknowledged being a heavy drinker, even when he starred as a player in the 1980s, but said he'd stopped drinking earlier this year after several hospitalizations.
He became a doctor after retiring from soccer and later became a popular TV commentator and columnist.
Socrates, whose full name is Socrates Brasileiro Sampaio de Souza Vieira de Oliveira, starred for the Corinthians team in the early 1980s, but he also played for Flamengo and Santos, as well as Fiorentina in Italy.
Besides serving as Brazil's captain in 1982, he was a member of its World Cup squad in 1986. The 1982 team became widely known as the best not to win a World Cup, falling to Italy, 3-2, in the second round despite needing only a draw to advance to the semifinals.
Socrates was included in soccer governing body FIFA's list of the best 125 living soccer players in the world, compiled by countryman Pele. Socrates played 63 matches with the national team, scoring 25 goals.
He was known for his great vision on the field. Always clever with the ball at his feet, his trademark move was the back-heel pass, and he set up and scored many goals with it throughout his career.