 This way of proceeding replaced the first step of Plantinga's earlier versions of the argument.The EAAN claims that according to naturalism, evolution must operate on beliefs, desires, and other contentful mental states for a biological organism to have a reliable cognitive faculty such as the brain.Eliminative materialism maintains that propositional attitudes such as beliefs and desires, among other intentional mental states that have content, cannot be explained on naturalism and therefore concludes that such entities do not exist.