 Critics note that walls are not computers; unlike a wall, a computer goes through state-transitions that are counterfactually described by a program (Chalmers 1996, Block 2002, Haugeland 2002). In his 2002 paper, Block addresses the question of whether a wall is a computer (in reply to Searle’s charge that anything that maps onto a formal system is a formal system, whereas minds are quite different). Block denies that whether or not something is a computer depends entirely on our interpretation. Block notes that Searle ignores the counterfactuals that must be true of an implementing system. Haugeland (2002) makes the similar point that an implementation will be a causal process that reliably carries out the operations – and they must be the right causal powers. Block concludes that Searle’s arguments fail, but he concedes that they “do succeed in sharpening our understanding of the nature of intentionality and its relation to computation and representation” (78).