The Definition of Disease

In her paper, Disease (2002) Studies in History and Philosophy of Biological and Biomedical Sciences. 33:263-282, Rachel Cooper defines disease as follows:

By disease we mean a condition that it is a bad thing to have, that is such that we consider the afflicted person to have been unlucky, and that can potentially be medically treated. All three criteria must be fulfilled for a condition to be a disease. The criterion that for a condition to be a disease it must be a bad thing is required to distinguish the biologically different from the diseased. The claim that the sufferer must be unlucky is needed to distinguish diseases from conditions that are unpleasant but normal, for example teething. Finally, the claim that for a condition to be a disease it must be potentially medically treatable is needed to distinguish diseases from other types of misfortune, for example economic problems and legal problems.

She is clearly rejecting more technical definitions, such as Boorse's 'interferences with natural functions' carried out by 'sub-systems of the body' for 'the overall aims of the organism', in favour of one couched in everyday language.

By ‘disease’ we aim to pick out a variety of conditions that through being painful, disfiguring or disabling are of interest to us as people. No biological account of disease can be provided because this class of conditions is by its nature anthropocentric and corresponds to no natural class of conditions in the world.

This definition makes an enormous difference when it comes to 'mental illnesses'. If one can be described in a way such that it is not construed as 'a bad thing', then it is not a disease. Cooper outlines Laing's account of schizophrenia:

According to this account it is us ‘normals’ who are truly alienated from ourselves. From childhood on we have been conditioned, first by our family, then at school, then at work, to act in ways that do not conform with our experiences, for example we are trained to be polite to people who offend us. Under such pressures we create a false self to present to the world. Schizophrenics are people who have refused to construct a false self and as such are better off than the rest of us. Their experiences are part of a healing spiritual journey that can potentially lead them away from normality and into a higher form of sanity. This account is also compatible with my own. Laing can be understood as claiming that schizophrenia is not a disease because it is not a bad thing and, if this were so, I would be forced to agree with him.

This conclusion is controversial to say the least, but it places our conception of what it is to thrive as a person at the heart of the matter, where it should be, rather than dressing it up in biological garb. Biology often puts in an appearance in the gaps where an author ought to be thinking in terms of ethics or politics.