 Whether or not they can ultimately be characterized as externalist, the views of Wittgenstein, Sartre and Heidegger play an important role in contextualizing the later development of externalism. Like externalism, they all occupy a position that can be labeled anti-Cartesian. They are all opposed to the idea that the mental processes had by an individual are always, and completely, determined by what is going on inside that individual’s body (or they expand the idea of the body in non-Cartesian ways, as in the case of Sartre and Heidegger). This type of view is not peculiar to philosophy. In psychology, expressions of the idea can be found in the work of the Soviet psychologists, most notably Vygotsky (1934 [1962]), and Luria and Vygotsky (1930 [1992]) and later in James Gibson’s (1966, 1979) development of an ecological psychology (see also Donald 1991 for a more recent development in this tradition). The roots of this anti-Cartesianism are not only broad but deep, predating Heidegger, and indeed the twentieth century. Gallagher (2018) argues that versions of this can be found in American pragmatism. It may be that the ultimate roots of this sort of anti-Cartesianism lie in Hegel (Crisafi &amp; Gallagher 2010; Boldyrev &amp; Herrmann-Pillath 2013). Whether or not this is correct, externalism—in either form—is best regarded as less an unprecedented eruption, and more as a recent expression of this historical tradition of anti-Cartesian thought.