Starting from a supposedly ‘liberating’ experience of man's being in modernity, a correlate of secularization, in this paper we present some essential traces of the profound anti-humanist critique -advanced in the twentieth century- of this ideal man already in acute crisis. In this sense, the current cultural experience largely considers that this ‘man’ ‘constructs’ himself from his will and freedom unanchored from God and truth, with the objective of a posthuman life. We maintain that this is an infrahuman neo-paganism, characterized by an immanentist, post-metaphysical and materialistic thought that does not recognize the reality of man and his transcendence - to a great extent, in power and politics or in the power of the technoscience of the transhumanist ideal - a truth in which he can only live with dignity and happiness. We will defend the importance of restoring the Christian -and more precisely Catholic- matrix for an integral formation of the person as authentic humanism.      We maintain that this is an infrahuman neo-paganism, characterized by an immanentist, post-metaphysical and materialistic thought that does not recognize the reality of man and his transcendence - to a great extent, in power and politics or in the power of the technoscience of the transhumanist ideal - a truth in which he can only live with dignity and happiness. We will defend the importance of restoring the Christian -and more precisely Catholic- matrix for an integral formation of the person as authentic humanism.Partiendo de una experiencia supuestamente ‘liberadora’ del ser del hombre en la modernidad, correlato de la secularización, en este trabajo presentamos algunos trazos esenciales de la profunda crítica antihumanista -avanzado el siglo XX- a este hombre ideal ya en aguda crisis. En este sentido, la experiencia cultural actual considera en gran medida que este ‘hombre’ se ‘construye’ a sí mismo desde su voluntad y libertad desancladas de Dios y de la verdad, con el objetivo de una vida posthumana.      Sostenemos que se trata de un neopaganismo, caracterizado por un pensamiento inmanentista, postmetafísico y materialista que no reconoce la realidad del hombre y su trascendencia -licuada en gran medida en el poder y lo político o bien en el poder de la tecnociencia del ideal transhumanista-, verdad en la que únicamente puede vivir digna y felizmente. Se defenderá la importancia de restaurar la matriz cristiana -y más precisamente católica- para una formación integral de la persona como auténtico humanismo.