 This core idea has been developed in several ways. Initial versions of externalism focused on semantics and mental content, holding that what some intentional mental states are about is at least in part determined by factors outside the body, including social arrangements, cultural patterns of expertise and deference, and norms that structure the division of linguistic labor (McGinn 1977; Burge 1979; Fodor 1987, 1994; cf. Putnam 1975a). Later and more contentious forms of externalism focused on the vehicles of content, holding that some cognitive processes and mental states are themselves located outside the head and body. According to this more “active” version of externalism, when a part of the environment or piece of technology becomes sufficiently integrated with an individual’s other mental processes, that bit of the world external to the skull is, strictly speaking, just as much a part of her mind as what’s going on in her brain. Her cognition extends into the world beyond her head.