ABSTRACT

In his new book From Empiricism to Expressivism: Brandom Reads Sellars (2015), Brandom offers a new argument against the viability of Sellars’ scientific naturalism, as the latter is famously expressed in the scientia mensura principle according to which “in the dimension of describing and explaining the world, science is the measure of all things, of what is that it is and of what it is not that it is not” (Sellars 1997, §42). A very interesting feature of this critique is that it utilizes explicitly and exclusively Sellarsian premises in order to reach its conclusion, suggesting thereby the possibility of a serious internal tension within Sellarsian philosophy itself. More specifically, Brandom uses what he calls the “Kant-Sellars thesis about modality” in order to argue against Sellars’ scientific naturalism, which privileges the descriptive and explanatory resources of the scientific image over those of the manifest image in matters ontological. Brandom shows that the Kant-Sellars thesis about modality implies an analogous thesis about identity, namely the “Kant-Sellars thesis about identity.” And this latter thesis, implying as it does that manifest-image objects cannot be identical to scientific-image objects, violates the scientia mensura principle, since, according to Brandom, this principle amounts to the claim that manifest-image objects exist only if they are construed as being identical to objects specifiable in the language of eventual natural science. I shall argue that, while it is true that the Kant-Sellars theses about modality and identity do violate the scientia mensura principle, as Brandom understands it (i.e., as an identity relation between the objects of the manifest and the scientific image), they are in fact fully consistent with the latter as Sellars understands it. This is because the relation between manifest-image objects and scientific-image objects is explanatory, and an explanatory relation is not one of identity. The fact that manifest-image descriptions are ultimately to be explained in scientificimage terms implies that phenomena described in manifest-image terms do not really exist, in the sense that they can be considered as implicated in causally efficacious phenomena (i.e., as providing adequate explanations) only if they are recategorized and ultimately understood in different , scientific -image terms.