Full Idea
The sentence 'Humanity belongs to Socrates' is about the concept of humanity, unlike the "equivalent" 'Socrates is human', so they express different propositions.
Gist of Idea
'Humanity belongs to Socrates' is about humanity, so it's a different proposition from 'Socrates is human'
Source
Donald Davidson (Truth and Predication [2005], 5)
Book Reference
Davidson,Donald: 'Truth and Predication' [Belknap Harvard 2005], p.102
A Reaction
[compressed] I like this a lot, because it shows why we should focus on propositions rather than on sentences, or even utterances. And asking what the sentence is 'about' focuses us on the underlying proposition or thought.
Related Idea
Idea 17308 Explaining 'Adam ate the apple' depends on emphasis, and thus implies a contrast [Schaffer,J]