Full Idea
In literary contexts semantically equivalent words cannot replace each other without loss of literary meaning.
Gist of Idea
In literature, word replacement changes literary meaning
Source
Roger Scruton (Public Text and Common Reader [1982], p.25)
Book Reference
Scruton,Roger: 'The Aesthetic Understanding' [Methuen 1983], p.25
A Reaction
The notion of 'literary meaning' is not a standard one, and is questionable whether 'meaning' is the right word, given that a shift in word in a poem is as much to do with sound as with connotations.