I argue against group agent realism, or the view that groups have irreducible mental states. If group agents have irreducible mental states, as realists assume, then the best group agent realist explanation of corporate agents features only basic mental states with at most one motivational function each. But the best group agent realist explanation of corporate agents does not feature only basic mental states with at most one motivational function each. So corporate agents lack irreducible mental states. How so? I (...) defend the conditional with an argument from disagreement. On cognitivist approaches to desire, desires function to both motivate and represent the world. Yet such desires are subject to a significant amount of disagreement. Reflection on the folk-psychological properties of desire and belief suggest that this disagreement is better explained by a non-cognitivist approach to desire where they do not have both functions. I then defend the claim that realists are committed to at least some cognitivist motivational states. Using the example of fire brigades, I argue that the best realist explanation of group agents involves mental states with both representational and motivational functions. By modus tollens, corporations then lack irreducible mental states, period. (shrink)