Full Idea
No matter how tight our account of coherence we have to admit that there may be more than one set of coherent propositions (as Russell pointed out (1907)).
Gist of Idea
Even with a tight account of coherence, there is always the possibility of more than one set of coherent propositions
Source
Jonathan Dancy (Intro to Contemporary Epistemology [1985], 8.2)
Book Reference
Dancy,Jonathan: 'Introduction to Contemporary Epistemology' [Blackwell 1985], p.113