This work is concerned with the enigma of the epsilon (E) which was carved at the entrance of the Temple of Delphes in ancient Greece. The author relates to a document produced by Professor Boris Rybak in "L'identité humaine" (1990, Michel Place ed., Paris), which traces the epsilon back to its Aegyptian Hieroglyphic source via the Proto-Sinaitic script and the ancient Hebrew script. The enigma dating 2.000 years back and evoked by Plutarch, may be considered solved (see the demonstration itself in the book) thus making a great contribution to science.