Full Idea
Self-evidence is often a mere will-o'-the-wisp, which is sure to lead us astray if we take it as our guide.
Clarification
A 'will-o'-the-wisp' deceives you and leads you astray
Gist of Idea
Self-evidence is often a mere will-o'-the-wisp
Source
Bertrand Russell (Mathematics and the Metaphysicians [1901], p.78)
Book Reference
Russell,Bertrand: 'Mysticism and Logic' [Unwin 1989], p.78
A Reaction
The sort of nice crisp remark you would expect from a good empiricist philosopher. Compare Idea 4948. However Russell qualifies it with the word 'often', and all philosophers eventually realise that you have to start somewhere.
Related Idea
Idea 4948 Intuition is the strongest possible evidence one can have about anything [Kripke]