Introduction

This article centres around two somewhat contrasting case histories: one involving a person with dementia; the other a person with mild mania.

The first case is of a man with dementia—probably due to Alzheimer's Disease. His personality changes so profoundly that his wife eventually says that he is not the same man as the man she married. I will suggest that there are three formulations of this: one is that the identity of the man with dementia is literally different from the man prior to the dementia; the second is that it is the same man but that his personality has changed and the third is that identity is not all or none, and that he is in part the same person, and in part a different person. These three formulations have different moral implications and none is, I believe, entirely satisfactory.

The second case is somewhat different. This is the story of a man who, when mildly manic, is different in important ways from when he is well. The question arises as to whether we should respect his wishes when manic or his wishes when well. This is not as straightforward as it sounds because when manic he is not, on traditional criteria, incompetent. Indeed, if there wasn't an alternative state we probably wouldn't recognise his manic state as abnormal.