Abstract

Recent developments under the keywords dynamicism, embodiment and situated cognition suggest the view that cognitive systems are not confined to the neural sys‐tem but leak into the world beyond the traditional system boundaries. This is the thesis of extended cognition. Such an extension of the cognitive vehicles leads to a new kind of content externalism, known as active externalism. The essay pursues three objectives: firstly, to distinguish the theses of extended cognitive and active externalism. Secondly, to delineate active externalism from its various passive-externalist precursors in the form of physical, historical and social externalism and to scrutinize its special position, which amounts to a comprehensive discussion and analysis of all variants of mental externalism. And thirdly, to show that social externalism as opposed to physical and historical externalism allows for a gradual transition from passive to active mental externalism.