 Mental content is not free-floating. Wherever there is mental content there is something that has it—a vehicle of content. Mental states (belief, desires, hopes, and fears, etc.) are natural candidates for vehicles of content. So too are mental acts (believing, desiring, hoping, fearing, etc.). As a rough, initial approximation, extended mind is the view that not all mental states or acts are exclusively located inside the person who believes, desires, hopes, fears, and so on. Rather, some mental states or acts are, in part, constituted by factors (e.g., structures, processes) that are located outside the biological boundaries of the individuals that have them. Thus, extended mind differs from content externalism not merely in being about mental vehicles rather than mental contents, but also in being committed to a claim of external location rather than simply external individuation. If extended mind is true, some vehicles of content are not, entirely, located inside the biological boundaries of individuals that have them. Rather, they are, partly, constituted by, or are composed of, factors that lie outside those boundaries. 