What is externalism?

The content of the externalist thesis about the mind depends crucially on how we define the
distinction between the "internal" and the "external". According to the usual understanding, the
boundary between the internal and the external is the skull or the skin of the subject. In this
paper I argue that the usual understanding is inadequate, and that only the new understanding
of the external/internal distinction I suggest helps us to understand the issue of the
compatibility of externalism and privileged access.