CONSIDER the expression ‘a good father’. While it is moderately clear in outline what sort of criteria go with this expression, it is not at all clear that an understanding of these is involved in understanding what it is to be a father. Nor is this merely because the idea of being a good father contains a reference to certain social conventions; for so, indeed, does ‘cricketer’ or ‘bank clerk’ – to know what a bank clerk is involves knowing a good deal about the social fabric in terms of which the role of a bank clerk is defined – but when I understand that role in those terms, I also understand in outline the sorts of things that a man would have to do in order to be called a good bank clerk. The difference with the idea of a good father is that it looks as though one can have a perfectly clear idea of fatherhood, and this not in itself lead one to an understanding of the sorts of things that make someone a good father. The explanation of this difference lies partly in the fact that the idea of fatherhood which we can grasp without grasping the evaluative criteria is an idea of fatherhood merely as a biological relationship; but it cannot be merely that idea which occurs in the notion of a good father.