Thomas Hobbes:
Hobbes defines justice in terms in term of a social contract in which a covenant is established without which any authentic judicial system is impossible. What Thomas Hobbes is actually questioning in his landmark work of literature titled “Leviathan” is whether it is possible such a covenant can exist when this social contract has been forcefully acquired and established or whether such a system of justice carries with it an implicit acceptance of the master/slave dynamic (Solomon, 1990, p.63-66).

John Locke:
In his “Second Treatise of Government” John Locke also questions the nature of justice by drawing a distinction between the organic and the constructed by raising the point that even if everyone in a society is born equal to everyone else, responsibilities and duties contrive to establish the social classes that impact how justice is implemented within any formalized system. Locke furthers cements this idea through the analogy of justice as a patriarchal system that resonates downward and outward through the system (Solomon, 1990, p.74-77).

Jean-Jacques Rousseau:
On the nature of justice, Jean Jacques-Rousseau is particularly fascinating at the moment because his concept of a social contract pointedly questions two underlying facets of democratic rule commonly, if not openly, accepted as the natural state of the process: majority rules should prevail and might makes right when that majority rule is threatened by perceived enemies of that system (Solomon, 1990, p.82-86).

G.W. Hegel:
When it comes to G.W. Hegel and the concept of justice, it is time to toss out the social contract of Rousseu and Hobbes and and implement a codified system of statutes that are devised not just for the individual violation, but for the larger sense of universal rights. The judicial system acts as the locus for addressing issues of universal morality through specific violations of conduct (Solomon, 1990, p.95-99). In this way, Hegel moves much closer to a view of justice as defined by Kant than by either Hobbes or Locke.

John Rawls:
“A Theory of Justice” sets out the definition of social justice proposed by Rawls very straightforwardly through a tripartite approach: the Liberty Principle, the Fair Opportunity Principle and the Difference Principle. These three principle all converge at the point of trying to make justice fair and equitable for all in reality rather than just through theory or lip service or claims to a higher social contract (Solomon, 1990, p.91-95). The spot where Rawls and Robert Nozick split most substantially is located in the realm of the Difference Principle. Rawls Difference Principle finds justice in economic inequality only when that inequality is permitted on account of its ultimately benefiting those otherwise disadvantages.

Robert Nozick:
In stark contrast to Rawls, Robert Nozick suggests that no economic inequalities can be considered an element of social justice when they are “permitted” since any justice applied to a system of voluntary economic transactions is by definition an unjust intrusion into the natural order of things. The definition of Robert Nozick is pared down to an even stricter degree than Rawls or Hegel, dealing mainly with the properties of respecting the rights of others. In particular, Nozick addresses the important of justice from the perspective of respecting the right to property and ownership (Solomon, 1990, p.96-97). In

J.S. Mill:
Mill is a dedicated proponent of the philosophical school of utilitarianism which suggests that the best route for any ethical decision is that which provides the greatest happiness for the greatest number. At the same time, he denotes justice as the one area where this philosophy finds its greatest obstacle. The problem being that the search for justice may well become merely a thirst for vengeance without the imposition of a greater good (Solomon, 1990, p.159-163). Mill’s utilitarian concept of justice disallows the category of a universal imperative that applies to all situations such as Kant’s views on justice require.

Immanuel Kant:
Kant’s consideration of justice is at the same time the easiest and the most difficult. What could be easier than a system of system of justice based on the categorical imperative that what is right for one must be right for all? The paradox being, of course, that what system of justice could be more difficult than one based on the idea that what is right for one situation is right every situation (Solomon, 1990, p.93, 212). While Kant’s categorical imperative would certainly seem to fit at home within the construct of a social contract for the good as envisioned by Rousseau or Hobbes, it can hardly be deemed useful in a utilitarian system of justice.

Karl Marx:
How can there ever be genuine justice in a capitalist system in which the system is designed and implemented by the owners to maintain control over the workers? As with all other social aspects, justice in philosophy of Karl Marx is subject the forces of economics in which those with the most to lose in a system of fair and equitable justice have the most power to ensure such a thing does not exist (Solomon, 1990, p.174-176). At the center of the Marxian view of justice is the concept of guaranteed individual rights. A system of justice based on extension of equitable individual rights is bound to come into conflict in a society with a justice system that places rights associated with property ownership at or above the level of rights associated with freedom of expression and the individual pursuit of happiness. This is social justice at its finest and is direct opposition to a system of justice that would be defined by Von Hayek’s rejection of social justice as pure mirage.

Friedrich Von Hayek
Hayek denies the possibility of social justice, which is actually to him a form of distributive justice that contains an ethical dimension. Distributive justice at its most basic can be considered a form of justice in which the allowance of essentially boiled down to the idea that the allowance of inequality may be considered a vital element to introducing and assuring the kind of utilitarian justice of which John Stuart Mill writes (Solomon, 1990, p.180-186). In the topsy turvy world of justice as describe by Hayek, the multitude of workers deserving of more justice in a system devised by Karl Marx would in fact received less justice due to the assumption that the owners put themselves at greater risk than the working class. Therefore, social justice would be denied in favor of a perverse form of justice distributed not on the basis of a social contract guaranteeing equality, but rather on that assumption that those placing themselves at greater economic risk are deserving of distribution of justice in direct ratio to the risk being assumed.