 In the philosophy of mind, externalism is the view that what is going on inside an individual’s body does not always, on its own, fix what is going on inside that individual’s mind. The mind, in this sense, simply denotes the totality of mental occurrences undergone by an individual at any given time. The body, in this sense, delineates the biological boundaries of the individual which, in creatures such as us, coincide with the individual’s skin and, of course, includes the brain, traditionally taken as the crucial determinant of an individual’s mental life. Thus, externalism is the view that an individual’s bodily (including neural) events, states, processes, etc. do not always, on their own, determine the mental, states, processes had or undergone by that individual. The qualifier not always permits there to be cases—perhaps many—in which mental occurrences are fixed by bodily occurrences. Externalism, generically at least, is merely committed to the claim that this does not always happen. The qualifier on its own is intended to convey that even if an individual’s bodily occurrences do not completely determine which mental occurrences are had or undergone by that individual, the former will at least partially determine the latter and, indeed, can play an important role in such determination. 