Full Idea
What complex of objects constitutes the fact that there is no bird on the bough, and how is that distinct from no squirrel on the bough? This drives us to see the world as composed of 'atomic' facts, making complexes into compounds, not reality itself.
Gist of Idea
Since 'no bird here' and 'no squirrel here' seem the same, we must talk of 'atomic' facts
Source
Michael Dummett (Thought and Reality [1997], 1)
Book Reference
Dummett,Michael: 'Thought and Reality (Gifford Lectures)' [OUP 2006], p.7
A Reaction
[He cites early Wittgenstein as an example] But 'no patch of red here' (or sense-datum) seems identical to 'no patch of green here'. I suppose you could catalogue all the atomic facts, and note that red wasn't among them. But you could do that for birds.