The paper contrasts Lennart Nordenfelt's normative theory of health with the naturalists' point of view, especially in the version developed by Christopher Boorse. In the first part it defends Boorse's analysis of disease against the charge that it falls short of its own standards by not being descriptive. The second part of the paper sets out to analyse the positive concept of health and introduces a distinction between a positive definition of health ('health' is not defined as absence of disease but in positive terms) and a positive conception of health (health is seen as an ideal). An objection against Nordenfelt's account is developed by making use of a specific example of an ambitious athlete. It is stated that Nordenfelt's conceptualisation includes too many phenomena under the umbrella of ill health. An ideal conception of health like Nordenfelt's is in danger of supporting medicalization. In conclusion, although Nordenfelt's theory is not altogether rejected and even seen in congruence with Boorse's account, it is claimed that the naturalistic framework should obtain conceptual priority.

Does the reference to a mental realm in using the notion of mental disorder lead to a dilemma that consists in either implying a Cartesian account of the mind-body relation or in the need to give up a notion of mental disorder in its own right? Many psychiatrists seem to believe that denying substance dualism requires a purely neurophysiological stance for explaining mental disorder. However, this conviction is based on a limited awareness of the philosophical debate on the mind-body problem. This article discusses the reasonableness of the concept of mental disorder in relation to reductionist and eliminativist strategies in the philosophy of mind. It is concluded that we need a psychological level of explanation that cannot be reduced to neurophysiological findings in order to make sense of mental disorder.

Ageing is often deemed bad for people and something that ought to be eliminated. An important aspect of this normative aspect of ageing is whether ageing, i.e., senescence, is a disease. In this essay, I defend a theory of disease that concludes that ageing is not a disease, based on an account of natural function. I also criticize other arguments that lead to the same conclusion. It is important to be clear about valid reasons in this debate, since the failure of bad analyses is exploited by proponents of the view that ageing is indeed a disease. Finally, I argue that there could be other reasons for attempting to eradicate senescence, which have to do with an evaluative assessment of ageing in relation to the good life. I touch on some reasons why ageing might be good for people and conclude that we cannot justify generalized statements in this regard.

The concept of mental disorder is often defined by reference to the notion of mental dysfunction, which is in line with how the concept of disease in somatic medicine is often defined. However, the notions of mental function and dysfunction seem to suffer from some problems that do not affect models of physiological function. Functions in general have a teleological structure; they are effects of traits that are supposed to have a particular purpose, such that, for example, the heart serves the goal of pumping blood. But can we single out mental functions in the same way? Can we identify mental functions scientifically, for instance, by applying evolutionary theory? Or are models of mental functions necessarily value-laden? I want to identify several philosophical problems regarding the notion of mental function and dysfunction and point out some possible solutions. As long as these questions remain unanswered, definitions of mental disorder that rest upon the concept of mental dysfunction will lack a secure foundation.