Jaspers’ account of the distinction between understanding and explanation connects together some suggestive ideas. Understanding, by contrast with explanation, is connected to empathy, to a shared subjectivity and imaginative projection. But whilst these are suggestive, it is not clear that they permit a clear distinction.
If the distinction is, as Jaspers claims, one of method not subject matter, is it clear that understanding has a different result from explanation? Does it place events in a different kind of pattern of intelligibility from explanation? If so, and if the guiding principle behind explanation is placing events in the context of natural laws, what is the guiding principle of undestanding? Jaspers does not say.
The most influential recent set of arguments for a distinction between human and natural sciences were developed in the 1960s drawing on the work of the Cambridge philosopher Ludwig Wittgenstein (1889-1951). One such influential work was by the philosopher Peter Winch (1927-98) in his The Idea of a Social Science.
Winch argues that there could be no such thing as a social science modelled on natural science. Human understanding cannot and should not be modelled on the natural sciences because it employs a different form of intelligibility. Winch argues that a central element of understanding meaningful behaviour is an understanding of the nature of rules. For this he draws on Wittgenstein’s discussion of rule following in thePhilosophical Investigations, §§139-239. This type of rule-following action can be as simple as a patient filling out a health history form. There are rules of veracity and restrictions against wild speculation concerning past diseases involved in providing a useful form.
Rules have a further important feature evident in this example. They are normative: they prescribe correct and incorrect behaviour. This is not the same as saying that most history forms are filled in at a particular time of day or night or by a particular socio-economic proportion of the patients with varying levels of usefulness. That may be discovered by empirical study. But the normative rules that characterise an event as an act of history-form completion are not provided by any such statistical generalisations. With these claims in place, Winch goes on to argue that the kind of understanding usually thought to make up social science is fundamentally dissimilar to natural science.
Winch followed Wittgenstein who had a profound influence on philosophy in the UK but much less so in the USA. But similar arguments are implicit in the work of US philosophers. Wilfrid Sellars (1912-89), for example, argued for a fundamental distinction between a natural scientific view of the world (or ‘scientific image’) and the ‘manifest image’. Building on Sellars’ work, John McDowell contrasts the logical space of reasons with the realm of law or of natural science. Donald Davidson draws a related distinction between the essential rationality of the mental realm and the physical. The former is governed by a ‘constitutive principle of rationality’ which ‘has no echo in physical theory’.
According to this group of philosophers, normativity cannot be accounted for in natural scientific descriptions of the world. Thus, on Winch’s assumption that the social or human sciences chart the rules that shape human behaviour, there is a fundamental distinction between them and natural science. But if it is right, it has implications for the fundamental rationality of understanding and that has consequences for understanding psychopathology and echoes of Jaspers. How can an assumption of rationality be squared with forms of mental illness which undermine rationality?