[There] is a basic attitude, I suppose, which underlies my writing—namely, that this is a wonderful universe in which to live, that it's great to be alive, and that all it takes is the willingness to give ourselves a chance to experience what life has to offer. If I preach at all, it's probably in the direction of individual liberty, which is a theme that looms large in my work….

[But my main job is to entertain the reader and] to hold his interest as best I can. I do this, primarily, by keeping the story moving. Since most stories have a basic content, though, I suppose they're bound to reflect certain philosophical overtones. And so, where I can, I try to say some-thing that I feel is important, such as the need for additional scientific research and development. (p. 44)

[Humor in my stories is] very important...