There is a rich philosophical literature on the value of equality: on whether and why it matters, what its “currency” ought to be, and whether it should be balanced against other important values, such as freedom, or conceptualized in terms of equal access to them. Most of this literature is a contribution to debates about distributive justice: it is concerned with how we should understand equality when our aim is to arrive at general principles of justice that could guide social or political authorities in distributing goods under their control. But there is also a different context in which we can, and do, ask about equality. Sometimes, when we ask whether someone has been treated equally, our aim is to assess whether they have faced discrimination. This is, of course, what courts and human rights tribunals do when interpreting constitutional or statutory equality rights – for these rights are usually understood not as general rights to equal treatment in the distribution of social goods, but rather as rights not to be discriminated against on the basis of a select number of prohibited grounds.