Beyond Knowledge of the Model

The principle motivation of this work is to display the sense in which the epistemic reading of a Kripke model tacitly requires common knowledge of the model, CKM. This requirement significantly restricts the amount of epistemic situations we are able to consider. We explore possible worlds epistemic models in a general setting without CKM assumptions and show that such models can be identified with observable substructures of Kripke models. We argue that such observable models offer a new level of generality and conceptual clarity in epistemic modeling. Similar analysis applies to intuitionistic models.