Investigating Thick Ethical Concepts – Philosophical and Empirical Perspectives

Philosophers distinguish between at least two types of evaluative concepts: thin and thick. Thin evaluative concepts, such as ‘good’ or ‘bad’, evaluate an entity positively or negatively, yet alone they provide no information as to why the entity is evaluated in this way. Thick concepts provide such descriptive information. Suppose that a close friend says the following thing to you: ‘What you did last night at the party was rude’. From this statement, you probably understand that your friend disapproves of your behaviour and evaluates it negatively. However, in contrast to simply calling your behaviour ‘bad’, you understand that your friend disapproves of your behaviour for being offensive, hurtful, or disrespectful. Terms such as ‘rude’ and ‘cruel’, or ‘friendly’ and ‘compassionate’, are examples of thick concepts. Thick terms and concepts are unique in that they provide both evaluative and descriptive content at the same time.

While thick terms and concepts have played a central role in many linguistic, metaethical, and ethical debates, they are still only poorly understood, and the field lacks any agreed-upon characterisation of what thick terms and concepts are – over and above the intuition that some terms and concepts are clearly thick. Additionally, what it is that these terms and concepts have in common is still subject to widespread disagreement. Attempts to characterise thick terms and concepts usually rely on example-based intuitions about how they are used in conversation. Surprisingly, the use of thick terms and concepts has not been examined empirically. We currently have no empirical evidence on how thick terms are and can be used in ordinary conversations, what speakers intend to communicate when using them, and what addressees understand them to communicate. To base philosophical discussions on empirically solid ground, we need a systematic empirical investigation of these matters. Moreover, the role and relevance of thick concepts in moral cognition is unclear. Philosophers ascribe to thick terms and concepts a vital role in moral language, thinking, and judging, and yet empirical evidence on ‘thick moral cognition’ is still lacking. This gap hinders not only progress in understanding moral language and thought but the phenomenon of normativity more generally.

The aim of this research project is to investigate the use of thick ethical terms and concepts in ordinary language and in moral cognition to provide a philosophically as well as empirically adequate characterisation. The first critical step of this project consists of analysing the current theoretical debate to identify shared assumptions and commitments, but also sources of disagreement about what characterises thick terms and concepts. Based on this theoretical analysis of the philosophical literature, empirically testable predictions are inferred. These predictions are examined using tools from experimental linguistics and psychology. The results of these studies are then discussed in light of their contribution to the philosophical characterisation of thick concepts and, eventually, a new characterisation is proposed. Equipped with this new, conceptually sharper, and empirically-grounded understanding of thick terms and concepts, the philosophical debates in which thick concepts have been used are reassessed.

This research project greatly improves our understanding of the nature of thick concepts, the relationship between the descriptive and evaluative dimensions of moral language, and normativity. This project is located at the intersection of philosophy, psychology, and linguistics, and thereby provides a new, innovative, and interdisciplinary approach to classical philosophical debates.

Project Leader: Dr. Pascale Willemsen
Accademic associates: Siu Hong Au