 Very critical and controversial, he published many articles, which brought him problems not only with Franco's regime but also with some of the mainstream Basque nationalism tendencies, because of his leftist social ideas.Gabriel Aresti was one of the greatest inspirers of the modern culture in Basque language (though he always found the sources in the popular culture and the daily talking, opposing to the purists of the language), and as a Member of the Academy of the Basque language, he defended the unified Basque language, which he also used before it was adopted by the Academy in 1968.He founded the publishing house Lur, allowing new authors in the Basque language like Ramon Saizarbitoria, Arantxa Urretabizkaia or Xabier Lete to publish their first works.