Full Idea
It is an apparent absurdity in proceeding ...through many rather recondite propositions of symbolic logic, to the 'proof' of such truisms as 2+2=4: for it is plain that the conclusion is more certain than the premises, and the supposed proof seems futile.
Gist of Idea
It seems absurd to prove 2+2=4, where the conclusion is more certain than premises
Source
Bertrand Russell (Regressive Method for Premises in Mathematics [1907], p.272)
Book Reference
Russell,Bertrand: 'Essays in Analysis', ed/tr. Lackey,Douglas [George Braziller 1973], p.272
A Reaction
Famously, 'Principia Mathematica' proved this fact at enormous length. I wonder if this thought led Moore to his common sense view of his own hand - the conclusion being better than the sceptical arguments?