Utopia

Utopia, in its most common and general positive meaning, refers to an imaginary, ideal civilization, which may range from a city to a world, regarded to be attainable in the future by some.

Human efforts to create a better, or perhaps perfect society are called utopianism. Ideas which could be/are considered able to radically better the world are often called utopian ideas.

"Utopian" in a negative meaning is used to discredit ideas as too advanced, too optimistic or unrealistic and impossible to realize. Hence, for example, the use by Marxists, of such expressions as "utopian socialism".