Full Idea
Having a belief demands in addition appreciating the contrast between true belief and false, between appearance and reality, mere seeming and being.
Gist of Idea
A belief requires understanding the distinctions of true-and-false, and appearance-and-reality
Source
Donald Davidson (Three Varieties of Knowledge [1991], p.209)
Book Reference
Davidson,Donald: 'Subjective, Intersubjective, Objective' [OUP 2001], p.209
A Reaction
This sets the bar very high for belief (never mind knowledge), and seems to imply that animals don't have beliefs. How should we describe their cognitive states then? I would say these criteria only apply to actual knowledge.