True Computation is only possible in a silicon substrate. Brains cannot compute. It might look as if a brain could compute, but brains can only simulate computation. Obviously, nature is not able to imitate the computation feats of a silicon processor, but just as a thought experiment, some philosophers have suggested that a brain could take in the same inputs as a silicon chip, and return the same results. But that would not be True Computation. Just as a simulated thunderstorm cannot make you wet, and simulated money cannot make you rich, simulated computation lacks an essential element that can only be supplied by the intrinsic powers of silicon transistors.