Individualism, twin scenarios and visual content

In this paper I address an important question concerning the nature of visual content: are the contents of human visual states and experiences exhaustively fixed or determined (in the non-causal sense) by our intrinsic physical properties? The individualist answers this question affirmatively. I will argue that such an answer is mistaken. A common anti-individualist or externalist tactic is to attempt to construct a twin scenario involving humanoid duplicates who are embedded in environments that diverge in such a way that it appears to be necessary to attribute divergent contents to their respective visual states. In the first half of the paper I discuss some of the twin scenarios that are prominent in the literature and argue that they fail to undermine individualism. Indeed I argue that due to important facts about our internal workings, a convincing externalist twin scenario involving humanoid protagonists cannot be constructed. However, I argue that such a result does not conclusively establish an individualist thesis and that in order to settle the question at issue it is necessary to construct an independently motivated theory of visual content. I attempt to do this in the second half of the paper by developing a theory at the core of which is the idea that the contents of our visual states and experiences are determined by the causal powers vis-