The fatal flaw of most utopian visions is that they're fundamentally static, and that's not a comfortable place for humans to live. Fourier was very good at imagining a utopia that is constantly changing and very busy, but a vision of paradise that would have been most tantalizing to an underfed overworked factory worker in 1840 doesn't have much appeal in fiction because it's not a story.

Because the utopian's worldview was framed around moving toward this perfected future, it helped stimulate the private exertions that add up to social progress. Progress is work. People need to build things and sacrifice and have a harder life for things to get better. On its own, I don't think even the most brilliant critique stimulates that kind of effort as well as an appealing vision of the future.

One of the things that's amazing about reading the private writing of these folks is that they enthusiastically describe things which we have now seen, and which are widely regarded as unappealing. They'll write, "It's going to be beautiful, we're going to have a town of 1,000 stone buildings that are all identical." And we as modern readers think, we've seen that; that's bad Soviet architecture or a public housing project. Nobody fantasizes about living there.

Some people think God is going to guide those humans. The Oneida community and the Shakers both believed that they had received revelations about how to build the New Jerusalem that the Bible says is coming

That to me was one of the most exciting, and weird puzzles of this book: how are the most religious people and the least religious people of their time all drawn to very similar visions of utopia?

The religious and irreligious are agreeing with each other almost all the time. Their rhetoric is the same, and their plans are the same. Through slightly different interpretations, they all think the same thing is going to happen, that the Earth is going to be perfected and that humans are going to do the work of perfecting it.

The thing that had fueled these utopian communities was a literal belief, and not just a general sense of optimism, that the earth was about to become a paradise. That idea cannot hold water after the war.