Matt Hughes asked:
You arrived at your distinctive style after a number of years in which you tried different approaches. You must have known that, while it would delight some, it was sure to put others off. That meant you would sell fewer books than plodders like Heinlein or Asimov. What made you do it?

Jack replies:

To tell the truth, I wrote the way I felt like... I just decided, the hell with it, Im going to write what I feel like writing, and forget trying to please John Campbell. I got tired of writing commercial trash, although I wasnt thinking in those terms, at the time.
I got tired of writing about cheap thrills in Science. Three-legged Joe was one of them- I had ice cold mercury being superconductive, and killing Three-legged Joe, because it was superconductive - that was a rotten story. There was one about, well, I wont go into it, I detest them all... Still, I wrote them, sold them, made a few bucks. I did as good a job as I could- some I think are pretty good- I like Miracle Workers, for instance, and Moon Moth. The Blue World, that was a gadget story; I dont like it much, the idea of making weapons out of iron distilled from peoples blood you dont need to do that- iron comes from what people eat, and in order to get iron, all you have to do is get it out of the stuff they eat!
"I would say Blue World was the last of my gadget stories, after that, I got more interested in people, like Navarth, and the protagonist of Tschai, and well, I wont go into details..