Should comprehensive diagnosis include idiographic understanding?

The World Psychiatric Association has emphasised the importance of idiographic understanding as a distinct component of comprehensive assessment but in introductions to the idea it is often assimilated to the notion of narrative judgement. This paper aims to distinguish between supposed idiographic and narrative judgement. Taking the former to mean a kind of individualised judgement, I argue that it has no place in psychiatry in part because it threatens psychiatric validity. Narrative judgement, by contrast, is a genuinely distinct complement to criteriological diagnosis but it is, nevertheless, a special kind of general judgement and thus can possess validity. To argue this I first examine the origin of the distinction between idiographic and nomothetic in Windelband's 1894 rectorial address. I argue that none of three ways of understanding that distinction is tenable. Windelband's description of historical methods, as a practical example, does not articulate a genuine form of understanding. A metaphysical distinction between particulars and general kinds is guilty of subscribing to the Myth of the Given. A distinction based on an abstraction of essentially combined aspects of empirical judgement cannot underpin a distinct empirical method. Furthermore, idiographic elements understood as individualised judgements threaten the validity of psychiatric diagnosis. In the final part I briefly describe some aspects of the logic of narrative judgements and argue that in the call for comprehensive diagnosis, narrative rather than idiographic elements have an important role. Importantly, however, whilst directed towards individual subjects, narratives are framed in intrinsically general concepts and thus can aspire to validity.