The concept of justice has multiple meanings, which can be in conflict. Alternative perspectives run from the ancient world to today, involving religion, philosophy, legal matters, economics and other social sciences, including many crossover views and views in utter conflict. Philosophers usually deal with justice, while economists and other social scientists may concentrate on fairness. Justice can be defined as moral rightness, based on philosophical, ethical, legal, rational, or religious principles. Fairness is being free from bias or injustice. I'm considering the two terms as roughly synonymous, especially in the realm of economics. Distributive justice is the proper allocation of income, goods, power, or wealth. Retributive justice requires proper punishment for wrong-doing.
Public policy issues can be viewed from a justice/fairness perspective (or multiple perspectives). A tax cut (or reform) can be described as needed for fairness (or resulting in extreme injustice). It depends on the relative perspective. The current tax system can be the status quo and changes based on that perspective: Does everyone benefit equally? Is everyone better off (e.g., gets a tax cut)? Will the economy as a whole be better off, say within five years? Does it meet specific goals of justice, such as a more equitable distribution or greater overall satisfaction? On the other hand does it violate specific tenets of fairness, such as inequitable effects, favoring the rich over the poor? Does it favor specific undeserving groups (e.g., big corporate lobbyists already paying much less than the statutory rate)?
Harvard philosophy professor Michael Sandel identifies three approaches to justice: The first approach is virtue, a Greek focus especially attributed to Aristotle. [Perhaps the term would be better translated as excellence.] Another perspective is maximizing utility (satisfaction or welfare), such as the maximum happiness for the greatest number of people. The third is the libertarian concept relating to freedom of choice, often associated with free markets. Justice can be promoting virtue, maximizing satisfaction, or promoting freedom. The three perspectives can lead to different interpretations and conclusions. Virtue can look like Immanuel Kant's categorical imperative; maximizing welfare with Jeremy Bentham's utility theory; and freedom of choice with Frederick Hayek's economic libertarianism.
The philosophies of ancient Greece seems a good place to start. In the Republic, Plato describes the "just state," which should be ruled by "philosopher/kings" understanding the meaning of a good life. Aristotle favored a life a moderation (the golden mean), focused on virtue (possibly excellence) and honoring the just life. Although democracy was born in Athens, neither philosopher was enthusiastic about its possible benefits. The Middle Ages saw the focus on Catholic teaching such as the philosophy of Thomas Aquinas. Aquinas' natural theology argued that reason is found in God and wisdom requires god's help. He identified the cardinal virtues as prudence, temperance, justice and fortitude.
The Renaissance and scientific revolution of Leonardo, Galileo, and Newton saw the increased interest in observation and empirical evidence as needed to draw conclusion; thus was born the scientific method of Bacon and others. The philosophers of the Enlightenment built on these. Thomas Hobbes developed the first social contract theory based on the contract with the king to bring peace and a civil society. John Locke's natural law had justice requiring consequences for actions and choice. Legitimate government required consent of the governed with rights to "land, health, liberty and possessions." Thomas Hume believed desires rather than reason ruled behavior, while ethics were based on experience and observation.
Perhaps the most influential of the Enlightenment philosophers on justice was Immanuel Kant, in part attempting to reconcile reason, experience and behavior. He developed a moral obligation theory of categorical (unconditional) imperatives including such things as never lying or committing murder. He believed in universal human rights and the imperative of treating all people with respect and dignity. People should be motivated by duty rather than self-interest, in direct opposition to Adam Smith.
Jeremy Bentham founded the utilitarian school, where welfare (utility) maximization produces the greatest happiness. John Stuart Mill expanded the theory, including the limits of control of government over the individual. Presumably all costs and benefits could be stated as "utils" to be optimized. "Neutral states" should respect individual preferences, especially related to property rights and civil liberties. Utility theory could be stated on an individual or societal level (which could be in conflict), but the concept of the greater good (for the greatest number) could lead to problematic behavior.
Libertarians incorporated much from both Adam Smith and utilitarianism, which increased the focus on personal choice. Individual choice topped the list of attributes, included government involvement only to promote free markets, laissez-faire, property rights and civil liberties. Frederick Hayek, a leading voice, favored bottom up approaches to government such as the evolution of common law in England. He opposed top down approaches such as civil law and the welfare states of Scandinavia. Monetarist economist Milton Friedman viewed the role of corporations to maximize profits irrespective of damage to society (including what economists called externalities such as pollution), but must follow existing laws and regulations. Libertarians opposed taxes to redistribute income, opposed aid to the poor or virtually any form of government aid.
John Rawls' A Theory of Justice viewed justice as fairness based on a social contract using a "veil of ignorance" (assuming each individual does not know his own role--presumably, people would oppose slavery if they could be a slave). The system should favor equal opportunity and governments should incorporate mechanisms (and incentives) to allow people to pursue their own interests.
Thus, ideas of fairness are diverse and no synthesis exists to balance all points of view. According to Michael Sandel (2009, p. 7): "the reach of markets, and market-oriented thinking, into aspects of life traditionally governed by nonmarket norms is one of the most significant developments in our time." Libertarian and utilitarian ideas are favored in this market view. Stay tuned. A large proportion of my writing emphasizes the scandals and corruption of this perspective. The best solutions, I believe, are greater regulation on corporate/business power (and incentives) and increased focus on social responsibility--also consistent with stakeholder capitalism.