 Arguing against 5 is Hintikka (1962), using his conception of epistemic alternatives. Having accepted T for knowledge, 5 stands or falls with the assumption of a symmetric accessibility relation. But, Hintikka argues, the accessibility relation is not symmetric: If the agent possess some amount of information at model set \(s_{1}\), then the model set \(s_{2}\) where the agent has learned something more will be an epistemic alternative to \(s_{1}\). But \(s_{1}\) will not be an epistemic alternative to \(s_{2}\), because in \(s_{1}\), the agent does by hypothesis not know as much as it does in \(s_{2}\). Hence the relation is not symmetric, so 5 is not a principle of knowledge, on Hintikka’s account.