 Externalism—whether of content or vehicle—is often viewed as a peculiar eruption of late twentieth-century analytic philosophy. This, however, is historically myopic. Cognate views with fairly clear externalist credentials have been advanced and defended much earlier than this, and in some of the defining works of twentieth-century philosophy (see Rowlands 2003: Chapters 3&amp;4). Wittgenstein (1953) argued that meaning something by a sign does not consist in an inner state or process. Rather, the possibility of such meaning depends essentially on the existence of a custom or practice of using a sign in given way, and the mastery of a technique—i.e., the ability to adjust one’s use of the sign to bring in into accordance with this custom. According to the dominant—community—interpretation of the notion of a custom, this entails that the possibility of meaning something by a sign is dependent on the existence of a practice external to the individual meaner, and that what this individual means by a sign on any given occasion depends, at least in part, on this external practice. As we shall see, this social version of content externalism was later developed, powerfully, by Burge (1979, 1986).