Full Idea
Two propositions might contradict each other despite appearing self-evident when considered separately.
Gist of Idea
Two propositions might seem self-evident, but contradict one another
Source
A.C. Grayling (Russell [1996], Ch.2)
Book Reference
Grayling,A.C.: 'Russell' [OUP 1996], p.42
A Reaction
Russell's proposal (Idea 5416) is important here, that self-evidence comes in degrees. If self-evidence was all-or-nothing, Grayling's point would be a major problem, but it isn't. Bonjour explores the idea more fully (e.g. Idea 3704)
Related Ideas
Idea 3704 Moderate rationalists believe in fallible a priori justification [Bonjour]
Idea 5416 If self-evidence has degrees, we should accept the more self-evident as correct [Russell]