Abstract
This chapter analyses the problem of free will and moral responsibility, to which the history of philosophy records three standard reactions. Compatibilists maintain that it is possible for us to have the free will required for moral responsibility if determinism is true. Others contend that determinism is not compossible with our having the free will required for moral responsibility – they are incompatibilists – but they resist the reasons for determinism and claim that we do possess free will of this kind. They advocate the libertarian position. Hard determinists are also incompatibilists, but they accept that determinism is true and that we lack the sort of free will required for moral responsibility. Source and leeway theories, and the notions of incompatibilism and libertarianism, are discussed.