tautology (noun) 

Tautology (taw-TAH-luh-jee) is saying the same thing in different ways; the needless repetition of an idea. As I used it today: “I have no doubt that listening to sad music moves people in positive ways. But… we still don’t know why. The explanations offered by researchers aren’t wrong, but they don’t feel like revelations. They are more like circular arguments – tautologies. Saying sad music is therapeutic isn’t any more informative than saying sad music makes you feel good.”