I remember reading some book a long time ago that defined a living creature as anything that "brings forth a world."

Interesting phrasing. Can you locate that book? A google search gives me a 'Santiago theory'.

The theory as you go on to explain it sounds more like empiricism, the idea that we are blank slates that get written on depending on what we encounter.

I've been awfully busy lately and haven't been giving as much attention to your posts! I vote them when I can, but don't read! I'll go and read the one you mentioned now.