When the conquerors arrived in the Valley of Mexico, they were amazed at the creations of the culture inherited from the Toltec tradition. With the prurpose of acknowledging this culture, this paper points out that words such as truth, thinking, and doubt have a very different connotation in modern European philosophy, to the Anahuac culture, which flourished in the Valley of Mexico between the 9th and 16th centuries. This writing presents a comparison of the process to obtain true knowledge according (...) to the rationality of the Nahua world of the 16th century and three authors of European modernity: Descartes, Kant and Hegel. Modernity is found to present a dominant and egocentric subject with self-referential thinking. In the Nahua culture the ideal is the man with a "heart of stone" and a "wise face" who seeks what is true, what has roots, and expresses it through poetry, “the flower and the song”. (shrink)