The philosophy that came after “the cogito” is very debatable, but you have to love how Descartes gets there, his deep skepticism, and the foundation of one’s thinking self. Philosophy at its best, before it got utterly unreadable. But in Persons and Bodies, Lynne Baker includes an argument that would modify Descartes’ ergo sum.
Baker’s Constitution View is thoroughly materialist and maintains that the mind is a product of higher brain functions.[1] Although the mind would not have to be constituted by an organic body, and thus her view would leave room for something of an immaterial soul (being, really), Descartes’ soul-body dichotomy and his epistemological conclusions are destroyed. In articulating her conception of what makes a mere human organism a person, Baker shows that not only could Descartes know that he himself exists, but that other things exist too. This because of the relational character of robust first-person perspective.
With one bit of simplified notation, here is her argument:
(1) x has a first-person perspective if and only if x can think of herself as herself.[2]
(2) x can think of herself as herself only if x has concepts that can apply to things different from x.
(3) x has concepts that can apply to things different from x only if x has had interactions with things different from x. [3]
Though Descartes questioned empirical knowledge, he did not question empirical categories. To have a sense of oneself as oneself, one must have interacted with other things. Therefore other things exist. Baker’s metaphysic is exceptionally elegant—it is so intuitive you can anticipate nearly every step. This argument is an unexpected and fascinating consequence of it.
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[1] Strictly speaking, Baker argues in terms of persons and mental properties. I’m re-centering the terms and concepts for this context.
[2] Following Hector-Neri Castaneda, the second personal pronoun is himself* (“himself star”), which marks an attributive first-person reference to oneself. In establishing strong first-person phenomena as the basis for personhood, Baker takes great care to explain this ‘reflexive’ notion as beyond simple perspective. But this is not needed here.
[3] Lynne Rudder Baker, Persons and Bodies: A Constitution View (New York: Cambridge University Press, 2000), 72
