  The lack of necessity attaching to causes made Ayer’s acceptance of human freedom undemanding. Having denied the existence of any causal necessity it was open to Ayer to be a compatibilist: determinism could be true (all action could be caused), but one could still accept that this left it open as to whether the agent could have done otherwise, given that the existence of the cause did not necessitate the action. Ayer argued that the relevant contrast to freedom was not causality, but constraint, or compulsion, which are a ‘special’ sort of cause. So if our actions could be caused whilst not being ‘constrained’ in any way, then determinism could be true and we could still be free. It was just as well that this position was available, claimed Ayer, because being held morally responsible for our actions required that these be not the result of sheer chance.