Antithesis
why this device works so well
Definition
Figure of balance in which two contrasting ideas are intentionally juxtaposed, usually through parallel structure.
Explination
Antithesis is a very effective rhetorical device, it contrasts two ideas to make a point and give your speech rhythm.
Examples
1. "It was the best of times, it was the worst of times" Charles Dickens, Tale of two cities
2. "One small step for a man, one great leap for man kind" Neil Armstrong, Apollo 11
3. " Time is money, but money can't buy time"
Neil Armstrong One Small Step For Man