The idea underlying many concepts of illness is that something has gone wrong with a biological system and some part of that system which has gone awry must be restored to it's proper function. The proper function of a biological systems is usually whatever allows that entity to live, breathe, exerts it muscles freely and vigorously without pain. When it comes to mental illness we extend that idea of proper functioning to anything that causes mental distress and is presumably due to biological problems with the brain. However there seems to me that something about that way of thinking is flawed because while it seems obvious when biological systems are disrupted rather than acting their natural course it does not seem obvious that mental distress is a product of biological aberrations. It seems rather like it is plausible that that is the normal course of life for humans even if that misery has a biological explanation.. So isn't mental illness essentially a flawed concept?

The definition of "illness" that you are using was originally developed by Christopher Boorse, and many others who have looked for an "objective" concept of illness have also adopted it. You are correct to say that on this view, all illness, including mental illness, is due to some dysfunction. And you are correct to note that we do not know (for most mental illnesses) whether or not there is a brain dysfunction. In fact, some have suggested that depression can be a functional response to failure and/or loss.

Different concepts of illness are worth considering here. For example, "subjective" concepts in which "illness" is defined as an undesirable or unwanted state. According to such definitions, there is mental illness when there is (serious)mental distress (since distress is undesirable or unwanted).

In practice, much can hang on whether or not something is labelled an "illness": medical treatment, insurance reimbursement, sympathy, excuses, responsibility, etc. That's really too bad, in my opinion, because "illness" is such a flimsy concept!

Hi, Miriam. I completely agree. The concept of illness is very flimsy. It is something like: an abnormality or disorder of a mental or physiological organ or system. Attempts to give a serious scientific account of 'normal' or 'orderly' have proved unsuccessful. Illness is just a vague folk notion and probably does not correspond to anything more scientifically or philosophically solid. Questions about the true underlying nature of specific mental illnesses (psychiatric disorders as they are now called), their treatment etc. are best deal with case by case. The same applies to physical illnesses though. There is nothing special about physiology here.

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