Why is the philosopher king necessary for the ideal state?

Q: Why is the philosopher king necessary for the ideal state? Why did Socrates hesitate to speak of it? What would be necessary for philosophers to become kings? (473d-e)

In Book V of Republic Socrates describes philosophers as lovers of wisdom who pursue the eternal idea of things: “lovers of the sight of the truth” (475e). Unlike the lovers of sight, who seek the representations of beauty in the unstable world of Becoming, philosophers strive to intellect and participate in the “fair itself” (476b). The Forms are not subjected to the flux of doxa because they are the supreme truths that structure reality: “knowledge naturally [depends] on what is” (477b). For Socrates, the tripartite soul will lead a healthy life if its parts are ordered by reason, which is “not any different from the just city with respect to the form itself of justice” (435b). Therefore, the ideal state must be governed by those with knowledge of the Forms, the ideas that are perfect and unchanging, who can establish balance and justice in the system using their reason—the philosophers.

In contrast with the warriors and money-makers, which are governed by spirit and desire respectively, the philosophers attempt to discover the truth to foster a common good (441e). Philosophers are indifferent to opinion and ambition because their soul is governed by reason: “a lover of learning... would forsake those pleasures that come through the body” (485d). For Socrates, the organization of the classes is analogous to the organization of the soul; to emulate the ideas and achieve the maximum collective happiness, the polis must be ruled by reason (368d, 443a). Since philosophers are ruled by reason and strive to uphold the common good (“what is best for the city”), they are destined to govern the kallipolis (412e). Attempting to satisfy all doxa would prohibit the formation of a just city; the strive for the universal idea and lack of a personal desire to govern is what makes philosophers the best rulers (479a-b, 520b).

What is best for the whole is what is most suitable for its parts: “assigning what’s suitable to each of them, we make the whole fair” (420d). Just as a limb needs the body to exist and to exercise in accordance with its natural purpose, the warrior (spirit) and money-making class (desire) need order, purpose, and education, which is established by the philosophers (reason), to live healthy and just lives: “better for all to be ruled by what is divine and prudent [if unavailable within] from outside” (590c-d). Therefore, the harmonious and happy city depends on the governance of those who uphold true justice and manage imperfection in the world of Becoming. The warrior and money-making classes recognize that they are better off governed by the stable and rational philosophers (in whom “political power and philosophy coincide”) because the happiness of their classes and the overall stability of the city depends on the fulfillment of a general justice, the “doing what’s appropriate”: the philosophers guard the whole city against the extremes of desire and spirit, the private ambitions of its individual parts (431e, 473d, 434b).

The city of Athens was notoriously hostile toward philosophers. Socrates hesitates, “afraid to speak,” before describing the anti-democratic sentiment: the necessity of a philosopher as king of the ideal city (472a). Unlike Athens, the first ancient democracy, Socrates envisioned the philosopher class as a special minority selected at birth and educated until the age of fifty (540a). In Book VI, Socrates uses an allegorical ship to describe the futility of a democratic state: those who hold the steering wheel are good with rhetoric but lack the knowledge needed to steer the vessel well (488a). Those who do not possess knowledge of the ideas “are by necessity excluded” from rule because the philosophers are the only citizens who have journeyed out of the cave and seen the sun—the eternal and most supreme Form of the Good (516b). A non- philosopher ruler, such as a rhetorician, would limit the city to doxa. Due to their weak nature and desire for private profits, the non-philosopher ruler would fabricate “shadows on the walls” for those chained to the dark cave (514a-b).

Once the sun is known, which is equated to the Form of the Good, returning to the cave becomes an endeavour both dangerous and unpleasant for the philosopher. The eyes, now adjusted to the sun, find the darkness disordering (517a). Unlike those in the cave, the philosophers are plucked and educated for the purpose of knowing the Forms and turning away from the Particulars: an effort to bestow knowledge onto those chained is equated to “putting sight into blind eyes” (518c). Once the philosopher sees the sun and discovers the truth, only law and duty (as repayment for his perfect education) can compel him to go descend into the cave and guide the people away from doxa and into “a state of waking” (520a). Although the warriors and money-markers will never know the ideas in their purest form, they will “receive the laws from [the rulers] ... like a dye” and reap the fruits of an established internal harmony generated by abiding with the philosopher’s knowledge (430a)

A philosopher is fitted by nature to practice both philosophy and to lead the polis. Unlike the lower classes, philosophers lack private property, family bonds, and private interests (416d-417b, 457d). They are motived by eternal truths, not inclined to indulge in personal desires, pleasures, or pursuits. Through proper education, they will be capable of discovering justice, a healthy harmony that orders and fulfills the natural capacities of the city hierarchy and of the tripartite soul. However, the philosophers must be compelled to rule as they are happiest away from the cave. By ruling the polis, philosophers maintain the universal order (“the good itself ... as a pattern for ordering the city”) that allows them to be happy and to continue studying the ideas (“we ought to paint eyes [and] the other parts [to] make the whole fair”) (540b, 420d). herefore, governing the kallipolis is not a desire but a disinterested duty.

For Socrates, philosophic rule is necessary to establish a natural and harmonious political order. The ideal city cannot come to exist unless philosophy and politics unite and maintain their union because philosophy is the best guide for forming a just polis: the rulers of the polis must be driven by reason and by love for what is. The noble lie told by the philosopher kings—the idea of each class corresponding to a different metal variant—allows them to establish a harmonious order analogous with the ordering of a happy, healthy soul (415a). The proper order is known only to those who intellect the Form of the Good and that of true, universal, supreme justice. As such, the philosophers are the only citizens who can be trusted to rule justly as it is in their nature to love the good itself and know the supreme knowledge necessary for a happy, healthy, and harmonious people.