Foreword by Philologist, late Mayor of Rethymno Dimitris Archontakis .

This book consists of three chapters. The first contains the views on first principles of pre-Socratic and post-Socratic philosophers. This presentation was deemed necessary in order to make a comparison of the relevant beliefs with those of Diogenes of Apollonia. The second contains information about the origin, life and work (in physics, astronomy, meteorology, mathematics and medicine) of Diogenes. The third chapter contains testimonies and excerpts from the works of various ancient authors about the life and work (mainly about this) of the Rethymnian philosopher.