 However, some argue that even if such an appeal to subjective indistinguishability is not enough to establish (CKA), it is nonetheless well supported by a causal argument (Robinson (1985)). We can suppose that when you see the snow-covered churchyard for what it is, there is some proximal cause of this experience: the experience is preceded by a certain sort of brain state B. But now we can imagine a situation in which we bring about B thus producing an experience in you, yet where B is not brought about through any interaction between you and a snow-covered churchyard—e.g., in laboratory conditions. In this scenario you have an hallucinatory experience as of a snow-covered churchyard. It is plausible to suppose that these experiences are of the very same kind given that they have the same proximal cause.