Fairness concerns itself with proportionality, not equality. It is a question of reciprocity – ‘just desserts’, what one deserves – rather than egalitarian distribution. Imagine you are working on a project with two colleagues, P and Q. P puts in a lot of effort, appearing to work beyond what would be expected in order to get the job done; Q appears to contribute very little to the project, is frequently missing from meetings, misses internal deadlines, and takes days off in the middle of the week to concentrate on their leisure activities. P, it seems to you, puts in just as much work as you do, if not more, whereas Q is not at all pulling their weight. Eventually, perhaps because of the efforts of P, and despite the efforts of Q, the project achieves its goals and attention turns to the question of remuneration. Is it fair that Q should be paid the same amount as you and P? To most people, it is not fair, and feelings of injustice or being wronged in some way are both natural and universal. This chapter will focus on how Shakespeare tends to depict such feelings as a key motivation for revenge and, if unchecked, a possible route to villainy, evil and even societal collapse. This is because the desire for revenge fuels selfish or self-seeking behaviour – the antithesis of fairness – and thus unfairness begets unfairness. Human groups that lack any sense of fairness and in which individuals have become wholly selfish cannot flourish. I will focus chiefly on Richard III's primary motivation for revenge, Hamlet's refusal to kill Claudius when he is praying, the Duke's pardon of Angelo in Measure for Measure, and Edmund's motivations in King Lear.

In a robust study, which cites over a hundred books and papers on fairness and equality from across psychology, sociology and evolutionary studies, Christina Starmans, Mark Sheskin and Paul Bloom have shown that, when all other factors are equal, human beings show a preference for equality of outcome, but this is almost always trumped by the principle of proportional fairness.