Models and Idealizations in Normative Inquiry

• Applicant: Marcel Jahn
• Subject Area: Practical Philosophy
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 558320807

Models are an indispensable tool across a wide range of academic disciplines. As idealized representations of a certain part of reality, they enable scholars to isolate and systematically study particular aspects of the world. To date, philosophers concerned with the use of models have primarily examined those models that pursue descriptive aims like deriving causal explanations or offering predictions. Recently, however, a growing number of scholars have shifted their attention to the use of models for normative purposes – i.e., models that help us address the question of what we ought to do. Despite the growing recognition of models in normative inquiry, the philosophical literature on the matter is still in its infancy, leaving many important questions largely unanswered. For instance, it is highly unclear how a modeling methodology fits within the broader enterprise of ethical theorizing. Moreover, it has been widely overlooked that models can serve quite different purposes within normative inquiry and – depending on their function – pose unique theoretical challenges. As a result of this, the literature has not yet paid sufficient attention to a central theoretical problem that arises specifically for those models that aim to justify normative verdicts: in virtue of what properties do these models – that play a crucial role in areas such as decision theory, formal epistemology, and climate economics – succeed in meeting their justificatory aim? In light of this situation, the primary goal of this project is to make a substantial contribution to the emerging and currently under-theorized field concerned with the use of models in normative inquiry. It aspires to offer the first comprehensive, in-depth analysis of these models by synthesizing previous work in the field and systematically addressing key philosophical challenges they present. In doing so, the project not only strives to develop concrete solutions to pressing methodological and meta-normative questions, but also to illuminate their broader implications for the practice of normative modeling. More specifically, the project aims to accomplish three main objectives. First, it seeks to address fundamental methodological questions by providing a detailed overview of the different types of models used in normative inquiry and situating them within the broader context of ethical theorizing. Second, the project aims to develop a solution to the core meta-normative issue that arises for those models that are employed to provide normative justification. Finally, the project intends to demonstrate the practical value of these theoretical insights for normative modeling. To this end, the project will involve a case study on climate economic models used to determine the social cost of carbon, illustrating how the theoretical resources developed in this project enhance our understanding and the utilization of these models.

• DFG Programme: WBP Position