Rhetorical Inversion

There is a psychological principle called the rhyme as reason effect. People, rather dispiritingly perhaps, are more likely to trust an idea when it's phrased musically. A j f ks, a first inaugural used a ancient greek rhetorical device called antimetabole - which is way too difficult to spell or pronounce. Ask not what your country can do for you, ask what you can do for your country.