 All my life, ever since I was a boy, I love science fiction. And there's this interesting thing in a lot of science fiction books. It's this trope called a generation ship. And this is a ship that travels great distances, like the distances between stars, at relatively slow speeds. And the people who start out on the journey don't live long enough to see the destination. It's their descendants who do. So generations of people grow up and get married and have children and die all aboard this ship, the generation ship. A few years ago I was thinking about generation ships for some reason. And I started asking myself about the operational problems of such a ship. Let's say that this ship is on its journey for, you know, 20 generations, 30 generations. Well, it's a complex machine. It's got systems that have to be maintained. Maybe it's got an exotic propulsion system, like a miniature sun or a caged black hole or, you know, something that, some kind of propulsion system that has no sense of humor. Something that has to be maintained correctly or else. And the question is, who will be there to remember, let's say five, six, seven, ten generations in? What should be done and why? And what shouldn't be done and why? Like you couldn't just start out with this general idea that you should do the right thing. That's not specific enough. You can't start out with the idea that the most important thing aboard this ship is the freedom to do whatever you want. You could say freedom is important, but that couldn't be the highest value. Because again, no matter what, these systems that keep the ship alive, that keep its inhabitants alive, have to be maintained until the ship gets to its destination. And so that got me thinking that the real problems of a generation ship aren't technical, really. They're moral. What should we do and why? What should we not do and why? And then I got to thinking that that's really what human civilization actually is. It's a generation ship. And tradition is how the builders of that ship speak to us. People who are no longer here, right? It's a kind of a testament of their hands and their minds. And that's what we mean, I think, when we say we're part of a civilization. It means we live in houses built by the dead.