Are Thick Concepts Action-Guiding?

In this project with Pascale Willemsen, we investigate the use of thick concepts in ordinary language. More specifically, we investigate whether statements containing thick terms provide reasons for action and motivate speakers and addressees of a moral statement to change their behaviour or stick to it.

According to authors such as Bernard Williams or Simon Kirchin, thick concepts are practical concepts which are both world-guided and action-guiding. They are world-guided in the sense that for an action to count as cruel, certain objective features need to be given, such as inflicting unnecessary pain or pleasure from the suffering of others. They are action-guiding in these sense that by calling an action cruel, we provide a reason not to perform this action.

While this is a quite plausible and seldomly disputed assumption, no empirical evidence has been offered in its support. The first aim of this project is, thus, to investigate whether laypeople understand statements containing thick terms as motivating, reason-giving, and morally evaluative.

In pursuing this first goal, we also collect data on an even more fundamental, yet never empirically tested assumption, namely that thin concepts are action-guiding. Many philosophers believe that thick concepts gain their action-guiding potential from the evaluation they share with thin concepts.

The experimental design we developed helps us test this hypothesis as well. A second aim of this project is, to see whether there is a difference between thick concepts and thin concepts to the extent to which they are action-guiding. Assuming that philosophers are correct in claiming that both thin and thick concepts are action-guiding, it is still an open and never empirically investigated question whether thin or thick concepts are more-action-guiding. Such evidence would yet go a long way in understanding evaluative language and their role in moral psychology.