Partly Cloudy

http://www.sxc.hu/photo/706719

But how are we to figure the change from ‘undecided’ to ‘true’? Is it sudden or gradual? At what moment does the statement ‘it will rain tomorrow’ begin to be true? When the first drop falls to the ground? And supposing that it will not rain, when will the statement begin to be false? Just at the end of the day, 12 p.m. sharp? … We wouldn’t know how to answer these questions; this is due not to any particular ignorance or stupidity on our part but to the fact that something has gone wrong with the way the words ‘true’ and ‘false’ are applied here.

— F. Waismann, “How I See Philosophy,” in H.D. Lewis, ed., Contemporary British Philosophy, 1956