Plato, Thomas Aquinas and Jeremy Bentham have exerted great influence over our ideas of justice and have spawned various schools of thought. This paper compares views on justice by looking at their writings on the ideal state and what constitutes moral behavior. Plato (427-327 BC) is one of the most famous philosophers of antiquity. In The Republic, Plato wrote of his concept of individual justice as an offshoot of what he sees as a tripartite soul. Plato believed that the human soul is divided into three elements. First, there are the bodily appetites, expressed through bodily needs such as hunger and thirst. Second are the spiritual elements, expressed through emotions like love, anger and compassion. Above all, the third element that separates people from animals and makes them unique is the human ability to use language and reason (Annas 1981).

An imbalance among these elements leads to conflict, sickness and misery. Individual justice can only happen when all three elements are in balance. Only when this balance occurs can a person live a just and harmonious life (Annas).

The theory of political justice parallels the theory of individual justice. For Plato, a city is "man writ large against the sky." Since people are social animals, cities are a natural extension and mirror of the human soul. In Plato's ideal society, each person's social role should be determined by the element dominant in his or her soul (Annas).

Thus, people who are ruled by bodily appetites should work as farmers, laborers, hunters and merchants. People ruled by spiritual elements should be members of a city's auxiliary and military staff. Finally, the men and women who are ruled by Reason should rule as society's guardians (Annas).

For Plato, political justice occurs when the guardians rule wisely and the other classes do their tasks, ensuring the smooth function of the social organism (Annas). As in the body, when all aspects of society function as one, there will be harmony. This harmony begets the reign of political justice, resulting in a state that is free from war or civil disorder.

Almost 1,500 years later, medieval philosopher Thomas Aquinas tried to combine Christian theology with the writings of Plato's successor Aristotle. Aquinas's most famous work, Summa Theologica, is an attempt to systematically reconcile Christianity with religion (Gilson 1994).

Unlike Plato, who believed that Reason is the purview of only the guardian class, Thomas believed that Reason came from God (Gilson). Therefore, Reason could belong to anyone who has faith.

Furthermore, Thomas argued that there should be no conflict between Reason and faith. He considered both of these concepts as gifts from God. The only difference is that reason gives rise to philosophy, while a combination of faith and divine revelations create theology.

Any conflict between these two components was supposedly the result of faulty thinking (Gilson).

While Plato believed that people ruled by bodily appetites and desires ranked low in the social hierarchy, Thomas believed that it is but natural for all people to desire happiness.

However, the deeply religious Thomas maintained that such happiness is only possible through direct communion with God. The Catholic sacraments were thus an important step towards helping humans turn away from sin and achieve communion with God (Gilson).

Given the importance of this communion, Thomas wrote that government has a moral responsibility, not only to serve the people's physical needs, but also to help them lead virtuous lives. The rulers should recognize that human laws can only be just when they do not contradict divine law. Furthermore, the government should never violate what Thomas maintained were God-given rights, such as the right to life, pain (Atkinson). A person must thus rein in this instinct, making sure that he or she acts morally, in ways that produce the greater good for the greater number of people.

This utilitarian philosophy led Bentham to agitate for reforming many of England's laws and institutions. Bentham believed that many current laws in England were geared to benefit only the rich, and were thus not just. Bentham believed that a government must always place the "general good" above any consideration for an individual's pleasure.

This Utilitarian philosophy can become at odds with other enshrined moral codes like Catholic theology. Bentham argued that many traditional standards of morality, like the Ten Commandments, were far too stringent. They required people to follow all principles, even when they will produce pain and hardship for the greater number of people. Bentham favored a more flexible moral code, one that allowed a person to make decisions based on the greater good (Atkinson).

Like Plato, Bentham believed the government is a mirror of the individual. Therefore, governments must also act in ways that promote the greater good of all its citizens, an early method of cost-benefit analysis.

In their own ways, each of these philosophers revealed a strong sense of responsibility to the community. They also advocated strict roles for the people who are chosen to govern.

Plato and Bentham both pessimistically conceived of humans as selfish creatures, who will act in their own interests or according to the needs of the soul that rules them. To solve this dilemma, Plato advocated a strict hierarchical society, where a learned and chosen few governed. Though the system was considered democratic 2,000 years ago, its weaknesses are more glaring today. First, the strict social hierarchy is inherently undemocratic. In Plato's ideal society, there is a tendency for social rank to be conflated with birth, giving rise to nepotism. It is unfair to deny people the right to participate in government because they give in to their natural human desires. It is likewise unfair to expect guardians to give up their worldly human desires simply because they are designated rulers. Plato's ideal society may function like a healthy organism, but its individuals are essentially devoid of freedom.

Bentham, on the other hand, placed a great amount of freedom in the hands of the individual. He made the idea of "the greater good" the arbiter of social good. In many ways, this measure has led to important reforms, such as women's suffrage. However, the lack of a social standard raises the potential for anarchy. The presumption that people will act towards the greater good assumes many things, among them that the person is well intentioned and well informed.

Bentham's idea of judging an action by its consequences is untenable. Many consequences are unintended. Besides, arguments for the "greater good" have led later utilitarians like Peter Singer to characterize abortion, infanticide and euthanasia as moral behavior.

A further weakness of Bentham and Plato is their neglect of an important aspect of human nature - the spiritual. Whether or not they believed God existed, the instinct to worship has been with humans since primitive times. Thomas Aquinas tried to address this failing by combining philosophy with Christian theology. This led him to espouse a more wholistic view of humans, that individuals must also lead a virtuous life.

My own personal philosophy incorporates much of Thomas Aquinas's concept of a virtuous life. Whether or not one is Catholic like Thomas, I…