In 1956, the French philosopher Maurice Merleau-Ponty—undoubtedly one of the most influential thinkers of our time—taught a series of three courses on Nature at the Collège de France. The one presented here to Spanish-speaking audiences is the first of these.

In the Prologue to the original French version, the editor, Dominique Séglard, explains that the text was compiled from typed notes taken by students who attended these classes. These notes were discovered by chance in the library of the École Normale Supérieure de Saint-Cloud, where they were stored in two notebooks whose call numbers indicated they had been cataloged in 1958. In addition to the notebooks, Séglard consulted Merleau-Ponty's personal notes to locate the cited authors—whose names were, in most cases, misspelled—and to restore, whenever possible, the citations and bibliographic references. After the library moved, the original notebooks appear to have been lost, leaving only two rather poor-quality photocopies. Despite this, Merleau-Ponty's thoughts were faithfully transcribed. Currently, all of the philosopher's personal notes are housed in the National Library of France.