A later poet may improve an inherited idea by clarifying its reasoning, condensing a difficult point, choosing a more apt example or revealing an implicit relationship.
Illustration: An earlier poet says hope keeps a person alive. A later poet presents hope as a lamp that guides a traveler through darkness. Their general meaning is related, but the second formulation adds a specific analogy.
This illustration is not a quotation from the source. Its point is that general resemblance of meaning must be assessed separately from the new expressive device.