contrasting relationship between two ideas
Antithesis emphasises the contrast between two ideas. The structure of the phrases / clauses is usually similar in order to draw the reader's / listener's attention directly to the contrast.
Examples:
- That's one small step for a man, one giant leap for mankind. (Neil Armstrong)
- To err is human; to forgive, divine. (Pope)
- It is easier for a father to have children than for children to have a real father. (Pope)