Abstract

Stapleford (2007) identified Johann Nicolaus Tetens as the missing link between Reid’s common sense treatment of external world scepticism and Kant’s transcendental Refutation of Idealism. While that account is arguably correct, it failed to recognize the distinction between being justified in believing P and being justified in believing that my belief in P is justified. This paper corrects the oversight and explains its implications. Tetens emerges as a weak externalist regarding knowledge of external objects, situated roughly halfway between Reid’s moderate externalism and Kant’s strong internalism.