Focus on this artwork and analyze the Overview.
Otto Brendel published in 1936 a book length study arguing that the scene should be interpreted by focusing on the sphere seen as central for the mosaic. His reading has been challenged by pointing that the object is actually the omphalos and the depicted gathering is located at Delphi. Others have emphasized that the central figure is Plato pointing with a stick at a celestial model. Mattusch (2008) suggests for the other figures, the Greek philosophers and scholars: Thales, Anaxagoras, Pythagoras, Xenophanes, Democritus, Eudoxus, Euctemon, Callippus, Meton, Philippus, Hipparchus, and Aratus. However, Mattusch also points out that the number of figures could relate to the Seven Sages of Greece, and points out that the sages often had fluid identities. David Sedley identifies the figures as Timaeus, Eudoxus, Plato, Xenocrates, Archytas, Speusippus and Aristotle.A strikingly similar mosaic has been found in Sarsina (now at Villa Albani) and as it has been dated after the volcanic eruption at Pompeii, a common source has been reasonably conjectured.  Also Rowe and Rees noted that a set of sculptures found at Memphis showed some similarity.
Democritus Otto Brendel Seven Sages Meton Pompei omphalos Timaeus Speusippus Aristotle Anaxagoras Euctemon Rowe Rees Hipparchus mosaic Xenophanes Pythagoras Villa Albani Xenocrates Thales Plato David Sedley Eudoxus Pompeii Callippus Aratus Memphis Philippus Delphi Archytas Seven Sages of Greece