José Luis Álvarez Enparantza ( 27 September 1929 -- 14 January 2012 ) better known by his pseudonym Txillardegi , was a Basque linguist , politician and writer .
José Luis Álvarez Enparantza ( 27 September 1929 -- 14 January 2012 ) was a Basque linguist , politician and writer . When writing he used the pseudonym Txillardegi .