Professor of Greek Philology at the Complutense University of Madrid, is the author of several work on the Presocratics. Among them are the book From Thales to Democritus. Presocratic Fragments (2001) and articles such as "The pre-Socratic philosophers and literary authors" (1979), "Models of time in pre-Socratic cosmologies" (1990) and "The One and the Many in Presocratic speculation: notions, patterns and relationships» (1998). About Orphism has published, among other studies, an edition of fragments (2004), the book Hieros logos. Orphic poem about the gods, the soul and the afterlife (2003) and, in collaboration with A. Jiménez San Cristóbal, Instructions for the afterlife: the Orphic gold lamellae (2001). About Orphism relations with philosophy, is the author of the work "Platone e l'Orphism" (1998) and the chapter "Orphism and Pythagoreanism 'of the History of Ancient Philosophy (coord. C. García Gual) (2004), within the "Ibero-American Encyclopedia of Philosophy» Editorial published in the same.