we lack justification for believing those facts; any appeal to experiential evidence will not decide the case against the sceptic. But, sceptics exaggerate the looseness of the connection between appearances and objects, for the connection is actually quite regular and law-like. The reason is that more than an experience is involved in perceiving something; there is the thing perceived as well. The natural relations between one’s beliefs and the environment also matter to a belief’s justification. A subject’s belief that there is a cat behind the flower pot is caused by the fact that there is a cat there; this fact is certainly significant to determining the justificatory status of the belief, even though this fact may not be reflectively accessible to one. Externalism stresses the justificatory significance of dependency relations between one’s belief and the environment (IEP, 2008). Moore stresses the importance of empirical proofs3 (Moore, 1962 in Sosa et al, 2008, 27) and thus, although he has not explicitly stated, one can correctly describe him as an externalist with respect to knowledge. In view of an externalist understanding of knowledge, Moore’s proof is perfectly legitimate. To conclude, there are two ways of understanding Moore’s proof, ‘externalist’ and ‘internalist’. The former is more sympathetic to Moore’s proof, but it relies on an externalist notion of knowledge, which Moore himself has not developed explicitly. The latter, in contrast, finds Moore to miss the point, and holds that an external world has not been proven. If one develops a new account of how knowledge is possible, then this knowledge will be immune from sceptic attack. Thus, the problem of scepticism is found to lie with the assumption about the nature of knowledge on which the argument rests. The source of Moore’s common sense response is in the different conception of knowledge which he assumes. Moore does not miss the point of scepticism – he has correctly identified it as a fundamentally mistaken doctrine. However, to do the question full justice, he should have developed more broadly an externalist theory of knowledge.
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