The Laws of Appearance are Still a Puzzle: A Reply to E.J. Green

A surface cannot appear both pure red and pure green at the same time, or both round and square at the same time. And nothing can appear square if it is red; there are conditional beliefs but not conditional experiences. In my book *Perception* and elsewhere, I raised the question: what explains such “laws of appearance”? I also noted that “representationalists” about experience may seem to have trouble explaining them. If we can represent in thought that something is round and square, or that something is square if it is red, why are we forbidden from representing these things in experience? In his article “Empirical Explanations of the Laws of Appearance” (this JOURNAL), E. J. Green suggests that representationalists can provide empirical explanations of the laws of appearance. Here I will explain why I think we should not yet accept Green’s approach. First (§1) I will show that Green’s approach requires rejecting “weak rationalism” and accepting “strong empiricism” about the laws of appearance. Then (§§2-3) I will question Green’s case for strong empiricism and explain why I think we should favor weak rationalism.