In this paper I construct a system of semantics for classical and intuitionistic propositional logic based on epistemic norms governing belief expansion. Working in the AGM-framework of belief change, I give a generalisation of Gärdenfors’ notion of belief systems which can be defined without reference to a logical consequence operator by using a version of the Ramsey Test. These belief expansion systems can then be used to define epistemic models which are sound and complete for either classical or intuitionistic propositional logic depending on which of the two notions of epistemic validity, identified by Levi and Arló-Costa, is used. Finally, I offer a discussion on how these results can be understood as providing a model theory within the framework of logical expressivism.

在本文中，我基于控制信念扩展的认知规范构建了经典和直觉命题逻辑的语义系统。在信念改变的 AGM 框架中，我对 Gärdenfors 的信念系统概念进行了概括，可以通过使用拉姆齐测试的一个版本来定义该信念系统，而无需参考逻辑结果运算符。然后，这些信念扩展系统可用于定义对于经典或直觉命题逻辑来说是健全且完整的认知模型，具体取决于使用由莱维和阿洛-科斯塔确定的认知有效性的两个概念中的哪一个。最后，我讨论了如何将这些结果理解为在逻辑表现主义框架内提供模型理论。