Full Idea
On white paper, the fact that a point is black corresponds to a positive fact; to the fact that a point is white (not black), a negative fact.
Gist of Idea
On white paper a black spot is a positive fact and a white spot a negative fact
Source
Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.063), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 08 'Judg'
Book Reference
Potter,Michael: 'The Rise of Anaytic Philosophy 1879-1930' [Routledge 2020], p.55
A Reaction
Elsewhere Wittgenstein is ambiguous as to whether he believes in negative facts [qv].