The Military Service of Plato: A List of Influential Factors

This list sets out the circumstances around Plato’s military service rather than claiming to know what the service itself involved. The one direct report is Diogenes Laertius III.8 (citing Aristoxenus, more than five centuries after Plato’s death): three campaigns, at Tanagra, Corinth and Delium, with a prize for valour at Delium. Since Delium was fought in 424 BC, when Plato (born c. 428/427 BC) was about three, the report cannot be right as it stands, and it may be confused with Socrates, who fought at Delium. Service as an Athenian citizen during the Peloponnesian War (431–404 BC) or the Corinthian War (395–387/6 BC) is likely. The points below are the factors that bear on it, and those that are inference are marked.

Leadership Training in the Ancient Greek Military

Athens did not train its young men for war from childhood, which was a Spartan feature. Athenian citizens were liable for service as hoplites or cavalry from about the age of eighteen, and most military skill was learned in the gymnasia, in the wrestling schools, and on campaign. Plato’s own gymnastic background is reported in the tradition: he is said to have wrestled, and Diogenes (III.4) cites Dicaearchus for his competing at the Isthmian Games, which is again a late report. For Athenian officers, command was by election, to the board of ten generals (strategoi) and to junior commands, and was held by prominent men, not by every soldier.

The claim that every Greek soldier received “leadership training” in loyalty, decisiveness and the ability to inspire others is therefore too strong for Athens. These qualities were admired, and the education Plato describes in the Republic for his ideal guardians is a literary design, not a description of Athenian practice. See the role of courage in Plato.

How Military Leadership Principles Influenced Plato’s Teachings

There is no evidence that Plato underwent “rigorous leadership training” or held any command, so it cannot be said that the army taught him discipline or teamwork. What the dialogues do show is that he cared about the formation of soldiers. In the Republic (374e–376c) the guardians are to be spirited and gentle, like well-bred dogs, and in Books II to IV their education in gymnastics, music and stories is planned to produce courage joined to gentleness. Plato’s ideal city also assigns roles by nature and aptitude, not by birth (the Republic allows children to move between classes, 415a–c), which is a departure from aristocratic Athens, and he may have been reacting to what he saw of Athenian politics. This is interpretation. The text does not tie that idea to any army.

On duty and responsibility, the Apology (28e) has Socrates compare philosophy to holding a post in the line of battle, which shows soldiering was a natural image for ethical duty. The allegory of the cave (Republic 514a–521b) is not about military leadership. It describes education turning the soul from shadows to what is real, and the philosopher’s duty to return and rule (519c–521b). Reading it as a story about command is a modern reading.

Cultural Norms in Ancient Greece

Cultural norms in ancient Greece plainly shaped Plato’s world. Greek society prized honour, courage and loyalty to the city, and the citizen-soldier was a central model of the good citizen, so Plato, who was born into a family of high rank, grew up with these values. That is a reasonable general statement. It would be unsafe to say more about exactly how he internalised them.

The high value that Athenian society placed on speech, argument and public debate is better documented. It created the setting for the Socratic conversations Plato wrote, and the sophists whom he criticises worked in the same culture. In that sense, the culture of debate, even more than the culture of the camp, is the strongest cultural influence on how Plato did philosophy.

Influence of Greek Values and Beliefs on Plato’s Worldview

The concept of arete, or excellence, was central to Greek culture, and Plato’s dialogues ask what it really is and whether it can be taught. The importance of paideia, or education, is an equally clear theme: the Republic is largely a programme of education. Plato also took over and criticised much of what he inherited, including the picture of heroes and warriors in Homer and the poets (Republic II–III and X; see Plato’s critique of poetry).

It is too neat to say that the Greek tradition of rational inquiry “laid the foundation” for the theory of forms. Plato’s own sources for his metaphysics include Socrates’ search for definitions (see how Socrates influenced Plato), and Pythagorean ideas about number and the soul, as in the older Italian philosophy whose teachers he is said to have visited. Those are the better-attested influences, and they have nothing specifically military about them.

Plato’s Relationship with Other Military Figures

Plato knew soldiers and commanders, though not as a comrade-in-arms so far as the evidence shows. His teacher Socrates served as a hoplite, not a commander, at Potidaea, Amphipolis and Delium, as Plato reports (Apology 28e; Symposium 219e–221c; Laches 181a–b). The mentorship of Socrates is the relationship that shaped him most. The Laches also puts two real generals, Laches and Nicias, in conversation with Socrates about courage, which shows how Plato thought about the questions soldiers face.

Beyond that circle, the Seventh Letter and later writers such as Plutarch show Plato in friendship with Dion of Syracuse, a statesman and relative of the tyrant Dionysius I, who in 357 BC led an armed expedition from Greece to overthrow Dionysius II (Plutarch, Life of Dion). Dion was Plato’s friend and, in the tradition, his pupil, and he was not a career soldier at the time they met. Plato also had a friendly connection with Archytas of Tarentum, a Pythagorean mathematician and statesman who, Diogenes Laertius says (VIII.79), was general of his city seven times.

Collaborations and Conflicts with Military Leaders in Plato’s Time

The relationship that clearly marked Plato’s political outlook was with his own relatives in the oligarchy of the Thirty. Critias, a cousin of Plato’s mother and a leader of the Thirty, was killed fighting the democratic exiles at Munychia in 403 BC (Xenophon, Hellenica II.4.19). In the Seventh Letter (324b–326b), whose authenticity is debated, Plato says that relatives invited him to join the regime and that he was soon disgusted by its violence, and then by the restored democracy’s execution of Socrates. Critias was a politician and intellectual first, not a military commander, and the Letter does not describe a personal quarrel with him. The Letter does present these events, and not any campaign, as what turned Plato from a political career towards philosophy.

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Related Links

Review of Plato’s Military Service and its Impact on his Philosophy
How did Plato receive education and mentorship?