Full Idea
The anti-realist view undercuts the ground for accepting bivalence. ...Acceptance of bivalence should not be taken as a sufficient condition for realism. ..They accept the weaker principle that unambiguous statements are determinately true or not true.
Gist of Idea
Metaphysical realists are committed to all unambiguous statements being true or not true
Source
Michael Dummett (Realism and Anti-Realism [1992], p.467)
Book Reference
Dummett,Michael: 'The Seas of Language' [OUP 1993], p.467
A Reaction
[cited by Kit Fine, when discussing anti-realism] I take it be quite an important component of realism that there might be facts which will never be expressed, or are even beyond our capacity to grasp or express them