Arrow's Impossibility Theorem is quite surprising. It shows that three very plausible and desirable features of a social decision mechanism are inconsistent with democracy: there is no perfect way to make social decisions. There is no perfect way to aggregate individual preferences to make one social preference. If we want to find a way to aggregate individual preferences to form social preferences, we will have to give up one of the properties of a social decision mechanism described in Arrow's theorem.

Hal R. Varian, Microeconomics: A Modern Approach, Chapter 33. Welfare, 2002