Man does not speak because he thinks; he thinks because he speaks. Or rather, speaking is no different than thinking: to speak is to think.
Source: Alternating Current, Andrp Breton or the Quest of the Beginning, 1967.
-- Octavio Paz, (Mar 31 1914-1998), Mexican poet, writer, diplomat; He is recognized as one of the major literary figures in Latin America after World War II. He received the Nobel Prize for Literature in 1990.