Normative vs. Descriptive Accounts in the Philosophy and Psychology of Reasoning and Argumenta-tion: Tension or Productive Interplay?

It is a longstanding insight (Hume, 1740) that the normative and descriptive are different in kind so that inferring an is from an ought or vice versa is fallacious. Just because there is litter doesn't mean there ought to be, and just because littering is an offence doesn't mean there won't be. However, closer inspection of many co texts involving norms (that is, standards of what we ought to do) suggests that the normative and the descriptive are less separate and less separable in practice than these basic considerations about 'kinds' suggest. This is apparent in attempts to make precise what gives standards their normative force. It is also apparent in the many context in which norms are applied in the context of descriptive research, such as research on human rationality within psychology or economics. And it is apparent in contexts where researchers seek to develop new norms for aspects of human behaviour that are not yet covered by norms of rationality even though it seems plausible that they would be. In all these cases, it is clear that the relationship between the normative and descriptive exhibits a breadth of interaction hat is neither properly catalogued nor systematically understood in the extant literature. These deficits are pressing because our normative projects themselves are far from complete, and they are widely drawn on in empirical disciplines. It is the premise of this proposal that progress could be made by tackling head on a fundamental issue that looms large in all of this: the issue of idealisation and abstraction.
The goal of the present project is to illuminate this aspect through a new perspective derived from considering science as a system dealing with idealisation. Humankinds' most highly developed system for dealing with the world is centrally confronted with the issue of idealisation and abstraction at every turn. We thus seek to import distinctions from science, such as that between framework, theory and model, to provide a new critical lens for the normativity issue. This will be cashed out in systematic analysis of extant research and in the context of a normative development case study, in which we seek to develop a new normative framework for testimony involving conditionals (e.g., you are told 'if you eat cheese before bed, you will have nightmares')--something we encounter daily in everyday life, that -remarkably- presently does not have an adequate normative treatment.
The project will develop the new perspective on the normative-descriptive relationship, evaluate extant research, and actively track the new perspective while conducting research aimed at developing an adequate normative account of the testimonial assertion of conditionals.