"Rawls challenged the view that utilitarianism, or some variant of social liberalism, was the only way to construct a social order. In A Theory of Justice, published in 1971, he laid out his alternative. Imagine, he postulated, that you have to make a choice about what social order you would want to be born into behind 'a veil of ignorance', in which you don't know beforehand your sex, skin colour, skills or the class of your parents. Your overriding concern would be to ensure that it was fair, because if you drew a short straw you would want to know that, as far as possible, society had structures that would redress the balance."