 In the same spirit, entities called “seemingly possible” worlds are introduced by Rantala (1975) in his urn-model analysis of logical omniscience. Allowing impossible possible worlds or seemingly possible worlds in which the semantic valuation of the formulas is arbitrary to a certain extent provides a way of making the appearance of logical omniscience less threatening. After all, on any realistic account of epistemic agency, the agent is likely to consider (albeit inadvertently) worlds in which the laws of logic do not hold. Since no real epistemic principles hold broadly enough to encompass impossible and seemingly possible worlds, some conditions must be applied to epistemic models such that they cohere with epistemic principles (for criticism of this approach see Jago 2007: 336-337).