One of the fundamental problems of philosophy is to specify the relationship between matter and reality. Zubiri, in a position that he describes as "materista", identifies, in a certain way, matter and reality. Everything apprehended has a sensitive moment (material) and a moment of reality (intelligible), without reality being reduced to the sensible. But Zubiri, especially in his later works, stresses that the sensible are not only the "contents" (white, etc.) shown by our senses, but also the "ways" in which those same contents are shown to us. The book tries to reactualize its "materista" thesis in light of this last analysis, which allows to rethink diverse material realities from elementary particles to man.