Abstract

An argument is offered that externalism can compromise the first‐person transparency of mental contents. The premises are John McDowell's view that experience is passively structured by concepts, and the Simple Theory of Colour advocated by John Campbell, according to which those properties that are the actual semantic values of colour concepts are just as they appear to normal observers under standard conditions. An example is offered to suggest that it must be an epistemic possibility that the semantic values of such concepts, as externally determined, are not the properties the Simple Theory takes them to be. The possibility highlights a mismatch between the properties that the colour concepts present as their semantic values and their actual, externally determined semantic values. Such a mismatch is shown to induce an incoherence into colour concepts leaving them unfit passively to structure our colour experience. Under such circumstances, it would not be transparent to a subject on the basis of colour experience, whether those experiences are conceptually structured by concepts answering to the Simple Theory, or precisely what content they carry.