Are Propositional Attitudes Mental States?

I present an argument that propositional attitudes are not mental states. In a nutshell, the argument is that if propositional attitudes are mental states, then only minded beings could have them; but there are reasons to think that some non-minded beings could bear propositional attitudes. To illustrate this, I appeal to cases of genuine group intentionality. I argue that these are cases in which some group entities bear propositional attitudes, but they are not subjects of mental states. Although propositional attitudes are not mental states, I propose that they are typically co-instantiated with mental states. In an attempt to explain this co-instantiation, I suggest that propositional attitudes of minded beings are typically realized by mental states.