His most important pedagogic work are "Introductio ad sapientiam" (1524); "De disciplinis", which stressed the urgent importance of more rational programs of education and studying; "De prima philosophia"; and the "Exercitatio linguae latinae", which is a Latin textbook consisting of a series of brilliant dialogues. His philosophical works include "De anima et vita" (1538), "De veritate fidei Christianae"; and "De Subventione Pauperum Sive de Humanis Necessitatibus" (On Assistance To The Poor) (1526), the first tract of its kind in the Western world to treat the problem of urban poverty and propose concrete suggestions for a policy of social legislation. Vives detected through philological analysis that the supposed author of the so-called Letter of Aristeas, purporting to describe the Biblical translation of the Septuagint, could not have been a Greek but must have been a Jew who lived after the events he described had transpired.