Metaphysicians, ethical theorists and philosophers of law squabble endlessly about what it is for a person to act — or perhaps even to ‘will’ — more or less freely. A vital issue in this controversy is how we should analyse two obvious but surprisingly problematical contrasts. The first antithesis is between things we do because we are forced, and deeds we perform because we want to — sometimes after having discovered preponderant reasons in their favour. The other polarity is more general. In most situations, if I act on my desire, I act more freely than if I had not had the desire. But what if my attitude is the product of childhood conditioning — or later brainwashing, brain surgery, hypnosis, behaviour modification, alcoholisim, narcotics addiction, neurosis, psychosis or worse? Then isn't my autonomy diminished? What is it about these latter desires, or their origin, that differentiates them from their unthreatening congeners?