As best as I can understand it, 'turtles all the way down' derives from some ancient cosmological notion of how the earth is held in place. In that notion, the earth is flat and round, sort of like a big dinner plate. It's held up on the back of an enormous turtle. What is that turtle standing on? -- on the back of another turtle. And what is that turtle standing on? -- on the back of another turtle. "It's turtles all the way down."
I love it! It works for me.
Now, combine that notion with my comment that "creation presupposes a creator, and who or what created him/her/it?", and you have a cosmology that looks like this:
"It's turtles all the way down; it's creators all the way up."
As unified explanations of everything go, it doesn't get any better.
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