Both Plato and Marcus had tried to raise the next generation of philosopher kings. Both had failed. This evidence may be anecdotal but scour through history and you will find the same story again and again. After a successful well respected ruler, the successor living in the shadow, often fails to live up to his predecessors reputation.
Now it is true, Plato presents a defense for the case of Commodus. His system of child rearing meant that no man knew who his parents were, and thus family loyalties could not usurp loyalty to the state. Even the wise Marcus had chosen his family over a safer more reasoned choice of successor.
But even without family ties, education is no guarantee of later character. All it takes is a few men of lesser character to take prominent positions in a state such as Kollipolis for everything to start unraveling at the seams. This kind of decay can be seen in the Roman revolution. At the final death throes of the Republic after a series of civil wars and prolonged political violence, the old moral values and education of the youth broke down.
So it is not that the Philosopher King is an impossibility. The combination of character traits required are simply so rare that it would be next to impossible to create a reliable lineage from one generation of kings to the next. Even if Plato were to have hundreds or even thousands of Guardians training in each generation, he can make no assurances that there will be one that has the qualities required to rule his state.
So am I denouncing the value of the Philosopher King as a ruler? Of course not! A look at the Roman Empire under Marcus Aurelius is enough to see the peace and stability brought to a peoples under such a rule. But a state cannot exist solely for the forced production of such a person. The reason? A Philosopher King must choose that path himself. It offers no benefit forcing philosophy upon the youth in hopes they may take it up. To create the perfect orderly soul Plato was seeking, they must be tempered in the imperfect, chaotic world. Only by rejecting the harsh nature of reality can one truly begin to follow the path to the Philosopher King. Take away the choice, and you’d destroy the very thing you were seeking to create.
A figure that portrays this better than any other is Siddhartha Gautama, better known as The Buddha. Born into an aristocratic family, the King built a palace for the young price where all the evils of the world would be kept at bay. He had everything he could ever want. The gardeners removed every dead flower and plant so that he would not learn of death. Travelling outside the palace in secret one day, he comes face to face with old age, death, disease, and other evils of the world. It was only after coming into conflict with these evils that he began his path to enlightenment.
It was conflict with suffering, exposure to the darkness, and the breaking of the lie that set The Buddha on his philosophical path. Just as it must be for the Philosopher King. Would Marcus Aurelius have had such a Stoic temperament if not for coming face to face with death so early on in life at the loss of his father? Would Plato, if not driven away from Athenian politics at the unjust execution of his mentor Socrates?
Uneasy lies the head that wears a crown.William Shakespeare, Henry IV Part 2
The Philosopher King is not an ideal that can be built hidden away in a Garden of Eden through a strict routine and education. Yes, these things are required but alone they are not enough. The soul Plato seeks can only be tempered in the wilderness and hides itself from all inspection. To reveal the Philosopher King we must first give him a throne – a dangerous decision if we have chosen poorly. But, only by ruling can the final pieces of Plato’s perfectly ordered soul be slotted into place. Only under the weight of the crown can the Philosopher Kings true nature be revealed.
So what is the answer? What is the perfect system? In truth, perhaps there isn’t one. Perhaps it is impossible to expect the flaws of human nature to be so easily dispensed with. The evidence points only in one firm direction: away from the rule of one. As long as a system relies on a solitary leader, it is far too easy for the system to break under poor leadership. It is only by having a balance of powerful forces that keep each other in check that a temporal stability can be enforced. This worked for the Romans: the Emperor, Senate, and Praetorian Guard were in a constant tug of war for control. The Spartans had two kings and a council called Ephors that judged their actions and had near equal power. In medieval europe it was the balance between Emperor and Pope that kept the wheel turning. And now, in our modern democracies, the various political parties vie for power.
Perhaps this is the best we can do. Hanging the sword of Damocles above our thrones while always preparing the next generation to take up the perilous seat. Just as a ruler judges his people, so too must the people judge their rulers.