Hybrid theories in metaethics hold at least one of the following theses: Moral claims express both belief-like and desire-like mental states.Moral judgments are constituted by both belief-like and desire-like components.
This definition is deliberately broad and inclusive, to cover all theories that share a theoretically important aspiration: to accommodate or at least explain away both the belief-like and desire-like features of moral thought and discourse without abandoning a broadly Humean philosophy of mind.
A broadly Humean philosophy of mind subscribes to two claims. First, that belief-like and desire-like states can be sharply distinguished in terms of their respective directions of fit: beliefs have a mind-to-world direction of fit (that is, beliefs aim to accurately represent the world), while desire-like states have a world-to-mind direction of fit (desires aim to have the world aligned with them). Second, that beliefs and desires are distinct existences: for any propositions p and q, believing that p and desiring that q can come apart. There are powerful arguments for this kind of view but, at the same time, moral thought and discourse have both belief-like and desire-like features. Hybrid theories take this appearance seriously and include both belief-like and desire-like elements in their theory at a basic level. In this way, they aim to accommodate or explain away the dual nature of moral judgments without abandoning a Humean philosophy of mind.
Traditionally, philosophers have supposed that moral judgments either a) are just Humean beliefs, and that moral claims express precisely those beliefs (cognitivism) or b) are just Humean desire-like states, and that moral claims express precisely those desire-like states (expressivism). Hybrid theorists are keen to emphasize that this supposition rests on a false dichotomy. Perhaps moral judgments are hybrid states, being partly constituted by beliefs and partly by desire-like states. Even if moral judgments themselves just are beliefs, moral claims might still in some important sense express desire-like states. Either of these ways of breaking free of the traditional debate might better accommodate or explain away the dual nature of moral thought and discourse within a Humean framework. The introduction of hybrid theories does not, however, dissolve the traditional debate completely. There are several theoretical issues on which hybrid theories could have more in common with traditional cognitivism than with traditional expressivism and vice versa. It is therefore useful to distinguish two types of hybrid theory: hybrid cognitivism and hybrid expressivism.
The Rights of Science and the Rights of Politics: Lessons from the Long-form Census Controversy
