On Husserl’s Twin Earth

Abstract

In a 1911 research manuscript, Husserl puts forth an idea that resembles Putnam’s Twin Earth thought experiment presented in the 1970s. In this paper, I study Husserl’s “Twin Earth” passage and assess various readings of it to determine whether Husserl is better understood as an internalist or an externalist. I define internalism as the view that content depends solely on internal factors to the subject, whereas I distinguish between two versions of externalism: weak externalism, according to which content can also depend on other subjects’ conceptions, and strong externalism, which maintains that content can also depend on the real world. Only strong externalism maintains what McGinn calls “the philosophical significance of externalism” because it entails realism about the world. I argue that Husserl is better understood as an externalist when it comes to the “Twin Earth” passage, but the more precise question regarding weak and strong externalism requires further evidence. This additional evidence concerns Husserl’s concepts of the identity of sense (Sinnesidentität) and worldly meaning (weltlicher Sinn). In evaluating externalist Husserl interpretations, I classify Smith’s externalist interpretation as weak, whereas I take Crowell’s externalist interpretation to be ambivalent. Crowell’s excellent but somewhat embryonic interpretation leaves the dependence relation between content and the real world ambiguous. I clarify this relation by assessing McGinn’s argument for the philosophical significance of externalism from the Husserlian viewpoint. Although this study is historical, it also serves a systematic purpose because the externalist interpretation of Husserl calls into question central issues in phenomenology and externalism.