Original position

The original position (OP), often referred to as the veil of ignorance, is a thought experiment often associated with the works of American philosopher John Rawls. In the original position, one is asked to consider which principles they would select for the basic structure of society, but they must select as if they had no knowledge ahead of time what position they would end up having in that society. This choice is made from behind a "veil of ignorance", which prevents them from knowing their ethnicity, social status, gender, and (crucially in Rawls's formulation) their or anyone else's ideas of how to lead a good life. Ideally, this would force participants to select principles impartially and rationally.
In Rawls's theory the original position plays the same role as the "state of nature" does in the social contract tradition of Thomas Hobbes and John Locke. The original position figures prominently in Rawls's 1971 book, A Theory of Justice. It has influenced a variety of thinkers from a broad spectrum of philosophical orientations.
Rawls coined the phrases original position and veil of ignorance. However, the same thought experiment had already been described earlier in social choice by William Vickrey and John Harsanyi, who independently derived proofs showing a rational observer in the original position would adopt a utilitarian framework.
The concept of the veil of ignorance has been in use by other names for centuries by philosophers such as John Stuart Mill and Immanuel Kant whose work discussed the concept of the social contract, Adam Smith with his "impartial spectator", or the ideal observer theory. John Harsanyi was the first to mathematically formalize the concept, using it to an argument in favor of utilitarianism rather than an argument for a social contract (as rational agents consider expected outcomes, not worst-case outcomes). The usage of the term by John Rawls was developed in his 1971 book A Theory of Justice.
Modern work tends to focus on the different decision theories that might describe the choice of the decision-maker "behind the veil". In addition, Michael Moehler has shown that, from a moral point of view, decision theory is not necessarily central to veil of ignorance arguments, but the precise moral ideals that are assumed to model the veil. From a moral point of view, there is not one veil of ignorance but many different versions of it.
Rawls specifies that the parties in the original position are concerned only with citizens' share of what he calls primary social goods, which include basic rights as well as economic and social advantages. Rawls also argues that the representatives in the original position would adopt the maximin rule as their principle for evaluating the choices before them. Borrowed from game theory, maximin stands for maximizing the minimum, i.e., making the choice that produces the highest payoff for the least advantaged position. Thus, maximin in the original position represents a formulation of social equality.
The reason that the least well off member gets benefited is that it is argued that under the veil of ignorance people will act as if they were risk-averse. The original position is a unique and irrevocable choice about all the most important social goods, and they do not know the probability they will become any particular member of society. As insurance against the worst possible outcome, they will pick rules that maximize the benefits given to the minimum outcome (maximin).
However, some scholars note that if the original position is formulated under risk neutrality rather than extreme risk aversion, the resulting principle shifts away from Rawls’s maximin approach and converges on a wealth-maximizing rule. In this respect, John Harsanyi’s analysis suggests that rational individuals, not knowing their future station but treating outcomes according to expected utility, would opt for maximizing average or total well-being. (See wealth maximization for further discussion of this approach.)
In social contract theory, citizens in a state of nature contract with each other to establish a state of civil society. For example, in the Lockean state of nature, the parties agree to establish a civil society in which the government has limited powers and the duty to protect the persons and property of citizens. In the original position, the representative parties select principles of justice that are to govern the basic structure of society. Rawls argues that the representative parties in the original position would select two principles of justice:
The reason that the least well off member gets benefited is that it is argued that under the veil of ignorance people will act as if they were risk-averse. The original position is a unique and irrevocable choice about all the most important social goods, and they do not know the probability they will become any particular member of society. As insurance against the worst possible outcome, they will pick rules that maximize the benefits given to the minimum outcome (maximin).
Recently, Thomas Nagel has elaborated on the concept of original position, arguing that social ethics should be built taking into account the tension between original and actual positions.
Recently, the original position has been modeled mathematically along Wright-Fisher's diffusion, classical in population genetics. The original position has also been used as an argument for negative eugenics, though Rawls's argument was limited to its use as a preventative measure.
In Anarchy, State, and Utopia (1974), Robert Nozick argues that, while the original position may be the just starting point, any inequalities derived from that distribution by means of free exchange are equally just, and that any re-distributive tax is an infringement on people's liberty. He also argues that Rawls's application of the maximin rule to the original position is risk aversion taken to its extreme, and is therefore unsuitable even to those behind the veil of ignorance.
In Liberalism and the Limits of Justice (1982), Michael Sandel has criticized Rawls's notion of a veil of ignorance, pointing out that it is impossible, for an individual, to completely prescind from beliefs and convictions (from the Me ultimately), as is required by Rawls's thought experiment.
In a 1987 empirical research study, Frohlich, Oppenheimer, and Eavey showed that, in a simulated original position, undergraduates at American universities agreed upon a distributive principle that maximizes the average with a specified floor constraint (a minimum for the worst-off in any given distribution) over maximizing the floor or the average alone.
In How to Make Good Decisions and Be Right All the Time (2008), Iain King argues that people in the original position should not be risk-averse, leading them to adopt the Help Principle (help someone if your help is worth more to them than it is to you) rather than maximin.
Philosopher and Law Professor Harold Anthony Lloyd argues that Rawls's veil of ignorance is hardly hypothetical but instead dangerously real since individuals cannot know at any point in time the future either for themselves or for others (or in fact know all aspects of either their relevant past or present). Faced with the high stakes of such ignorance, careful egoism effectively becomes altruism by minimizing/sharing risk through social safety nets and other means such as insurance.