Dis-ease about kinds: reply to D'Amico.

In The Nature of Disease I argued that a value-free account of our concept of disease cannot be given. Part of this argument consisted in showing that diseases as a class do not constitute a natural kind. To understand this, we need only see that we define and classify conditions into diseases and non-diseases not in terms of their causes but in terms of their effects. While no philosophical position is watertight, the arguments overwhelmingly favour the conclusion that diseases do not constitute a natural kind.