What you will have I’ll give, and willing too;
For do we must what force will have us do.
Shakespeare, Richard II, 3.3.204–05
The idea that freedom consists in the absence of constraints and the question of what counts as a constraint on freedom are central themes in social and political philosophy. There is, for example, the debate between liberals and neo-republicans. Neo-republicans accuse liberals of focusing on actual unjustifiable interference in the lives of others. This liberal freedom is purely ‘negative’ in that it consists only in the absence of such interference. Protecting this freedom will require the removal and prevention of constraints of the relevant type, leaving individuals free to do what they desire to do, even though they may lack the ability or power to do it....