There have been many utopias based on politics, economics, religion, ecology. Some of these have been propagated in books and pamphlets, some as actual communities. In practice, attempts to create utopias seem doomed, as good intentions run against problems. Most of the literary utopias are actually satires of existing societies. There were several attempts to create such perfect societies (they did not work). The word utopia can also refer to a society of such an attempt.