It might seem surprising that our consideration of consent to treatment did not directly tackle the question of refusal of consent. After all, it might be said, these are merely opposite sides of the same coin. In many ways this is true, but – as will be seen – there are both ethical and legal complexities in respect of refusal of treatment that justify its separate consideration. In some cases, the consequences of failing to accept treatment may be no more than mildly disturbing. In many such cases, the patient's health will recover, albeit, perhaps, more slowly. In others, however, refusal of treatment may amount to a life-threatening decision which tests the doctor's dual commitments, on the one hand, to respect the autonomy of the patient and, on the other, to maximising his or her health.

The law on this subject appears to be clear, at least where the individual patient has the necessary legal capacity – a question that is discussed briefly below and in more detail in Chapter 15. A sane, adult patient can refuse even life-saving treatment on grounds that are rational, irrational or unknown. In other words, the reason for the decision is not open for scrutiny or debate; put simply, a competent decision once made must be respected. If, indeed, the law is so clear, then why does it require consideration?