In the Ibero-American world, besides Xavier Zubiri, there is no other thinker known who has expressly dealt with deciphering and clarifying the ontological condition of the eidos. Obdulio Banda, faithful to his bold and daring style, ventures to investigate the ontological legitimacy of the eidos, and concludes that what is called eidos is nothing but a creation of the mind. He refutes the whole traditional conception of the eidos. His work is eminently argumentative, critical and original; it marks a turning point in the study of the eidos.