Mental illness, concept of

The mad were once thought to be wicked or possessed, whereas now they are generally thought to be sick, or mentally ill. Usually, this is regarded as a benign decision by a more enlightened age, but some see it as a double-edged sword – one that simultaneously relieved and robbed the mad of responsibility for their actions, eventually delivering more compassionate treatment, but also disguising value-laden judgments as objective science. The issue is made more difficult by the diversity of conditions classified as psychiatric disorders, and by the extent to which their causes are still ill understood. But the difficulty is also conceptual: what, after all, is physical illness? People usually agree that it involves abnormal body functioning, but how do we decide what is normal functioning? And even supposing that we know what we mean by a sick body, is there a parallel notion of a sick mind that is more than metaphor?