Aristotle ( 143c, Plato announces through his characters that he will abandon the somewhat cumbersome dialogue form that is employed in his other writings.
Since the form does not appear in a number of other writings, it is reasonable to infer that those in which it does not appear were written after the Scholars have sought to augment this fairly scant evidence by employing different methods of ordering the remaining dialogues.
Once again, however, things in Syracuse were not at all to Plato's liking.
Dionysius once again effectively imprisoned Plato in Syracuse, and the latter was only able to escape again with help from his Tarentine friends ( 350a-b).
Nonetheless, it is plain that no influence on Plato was greater than that of Socrates.
In spite of the confusion, the dates of Plato's life we gave above, which are based upon Eratosthenes' calculations, have traditionally been accepted as accurate. According to Diogenes, whose testimony is notoriously unreliable, Plato's parents were Ariston and Perictione (or Potone—see D. While he stayed in Syracuse, he became the instructor to Dion, brother-in-law of the tyrant Dionysius I. The first of Plato's remaining two Sicilian adventures came after Dionysius I died and his young son, Dionysius II, ascended to the throne. Dionysius then summoned Plato, but wished for Dion to wait a while longer.Regarding the sensibles, he borrows from Heraclitus; regarding the intelligibles, from Pythagoras; and regarding politics, from Socrates. Diogenes Laertius (3.6) claims that Plato visited several Pythagoreans in Southern Italy (one of whom, Theodorus, is also mentioned as a friend to Socrates in Plato's Plato has Echecrates, another Pythagorean, in the group around Socrates on his final day in prison.Plato's Pythagorean influences seem especially evident in his fascination with mathematics, and in some of his political ideals (see Plato's political philosophy), expressed in various ways in several dialogues.Dion subsequently gathered an army of mercenaries and invaded his own homeland.But his success was short-lived: he was assassinated and Sicily was reduced to chaos. The effects of this influence can perhaps be seen in the mature Plato's conception of the sensible world as ceaselessly changing.