GREECE - DECEMBER 13: On October 15, 1930, the famous olive tree of Athens where the great philosopher of Greek antiquity, PLATO, came to preach nearly 2,500 years ago. (Photo by Keystone-France/Gamma-Keystone via Getty Images)

GREECE - DECEMBER 13:  On October 15, 1930, the famous olive tree of Athens where the great philosopher of Greek antiquity, PLATO, came to preach nearly 2,500 years ago.  (Photo by Keystone-France/Gamma-Keystone via Getty Images)