Editing G. E. Moore (section)

===Proof of an external world===
{{Main|Here is one hand}}
One of the most important parts of Moore's philosophical development was his differing with the [[idealism]] that dominated British philosophy (as represented by the works of his former teachers [[F. H. Bradley]] and [[J. M. E. McTaggart|John McTaggart]]), and his defence of what he regarded as a "common sense" type of [[Philosophical realism|realism]]. In his 1925 essay "[[A Defence of Common Sense]]", he argued against idealism and [[scepticism]] toward the external world, on the grounds that they could not give reasons to accept that their metaphysical premises were more plausible than the reasons we have for accepting the common sense claims about our knowledge of the world, which sceptics and idealists must deny. He famously put the point into dramatic relief with his 1939 essay "Proof of an External World", in which he gave a common sense argument against scepticism by raising his right hand and saying "Here is one hand" and then raising his left and saying "And here is another", then concluding that there are at least two external objects in the world, and therefore that he knows (by this argument) that an external world exists. Not surprisingly, not everyone preferring sceptical doubts found Moore's method of argument entirely convincing; Moore, however, defends his argument on the grounds that sceptical arguments seem invariably to require an appeal to "philosophical intuitions" that we have considerably less reason to accept than we have for the common sense claims that they supposedly refute. The "Here is one hand" argument also influenced [[Ludwig Wittgenstein]], who spent his last years working out a new method for Moore's argument in the remarks that were published posthumously as ''[[On Certainty]]''.)