Father Soloeta-Dima wrote his Curso primero del idioma basko en dialecto guipuzkuano (Buenos Aires, 1912) for his Basque language course at Euskal Echea of Llavallol. This paper analyzes the ideas of language in this school grammar, focusing on how they reflect some core concepts of the so-called 'Basque Renaissance': grammar logicism, lexical purism and political nationalism. These three concepts inform the thought of Sabino Arana Goiri, considered as the founding father of Basque nationalism. Arana had a noticeable influence on Soloeta-Dima's grammar, as shown by some of the tenets in its description of the Basque language - absence of prosodic features, result of some vowel clusters, deletion of genitive suffix, extension of synthetic verb forms -, by the radically purist ideas about the lexicon - no loans from Latin or romance languages, abundance of neologisms (most of whose sources have been identified) -, and by the nationalist perspective illustrated by some of the examples in the grammar. [ABSTRACT FROM AUTHOR]