A) In the field of pedagogical literature

It is true that Calasanz was not an educational theorist, and he left very few documents in which he gave a systematic account of his educational theory. Nevertheless, his educational thougts are reflected in the Rules and Constitutions of the Pious Schools. They include some words in defense of the education of the poor and a brief summary of the way he wanted teaching in his schools to be performed.

In 1610 Calasanz wrote the Documentum Princeps (Princely Document) in which he set out the fundamental principles of his educational philiosophy. The text was accompanied by regulations for teachers and students.

But the largest and most complete source for studying his educational theory is his letters. Over 4,700 of them have been preserved and published. In them, one can find many norms and pedagogical suggestions, derived from both his personal practices and his correspondence with his companions.

Calasanz himself was able to write in four languages: Spanish, Catalan, Latin and Italian. He wrote a catechism for the amallest ones, and he composed The Crown Of The Twelve Stars- a prayer full of pedagogical meaning written in honor of Mary.

He also inspired the following four great works, written by his friends in defense of the Pious Schools: Book about the Piarist Pious Education by the Spanish Carmelite Juan of Jesus and Mary; Apologetic Book of the Pious Schools by the Italian Dominican, Tomas Campanella; An Apology of the Pious Schools by the Piarist Father, F. Castelli; and In Defense of the Pious Schools by the Lawyer F. Finmiani.