Response to: Correspondence on 'No, pregnancy is not a disease' by Colgrove and Rodger

Colgrove and Rodger argue that the case advanced by Smajdor and Räsänen for classifying pregnancy as a disease can be defeated by an existence proof-that is, by identifying at least one plausible theory of disease that excludes pregnancy while avoiding objections raised by Smajdor and Räsänen. Their candidate is a dysfunction account, according to which a disease requires the failure of some internal mechanism to perform its biological function. Pregnancy, they claim, involves no such failure. Even if one accepts the legitimacy of this dialectical strategy, the proposed exclusion is not as simple as advertised. In particular, the exclusion is obtained by narrowing the target phenomenon and by treating the concept of 'proper function' as if it had a determinate, value-free extension-one that it in fact does not possess. Since the apparent dialectical effect of an imperfect rebuttal can be to strengthen rather than weaken the target of criticism, I find it worth responding to both pieces in a single, joined-up analysis, which I aim to present here.