This passage from Stephen Hawking’s book A Brief History of Time explains the origin of the phrase “turtles all the way down.”
A well-known scientist (some say it was Bertrand Russell) once gave a public lecture on astronomy. He described how the earth orbits around the sun and how the sun, in turn, orbits around the center of a vast collection of stars called our galaxy. At the end of the lecture, a little old lady at the back of the room got up and said: “What you have told us is rubbish. The world is really a flat plate supported on the back of a giant tortoise.” The scientist gave a superior smile before replying, “What is the tortoise standing on?” “You’re very clever, young man, very clever,” said the old lady. “But it’s turtles all the way down!”
It’s possible the old lady’s objection was in response to Bertrand Russell’s comment:
If everything must have a cause, then God must have a cause. If there can be anything without a cause, it may just as well be the world as God, so that there cannot be any validity in that argument. It is exactly of the same nature as the Hindu’s view, that the world rested upon an elephant and the elephant rested upon a tortoise; and when they said, “How about the tortoise?” the Indian said, “Suppose we change the subject.”
As far as I can tell the story hasn’t been verified as historical fact, but I think it’s a great point to launch a discussion from — namely, a discussion about the infinite regress argument.
Creationism (and intelligent design, essentially the same thing) states that anything complex has to have been created. There’s no free lunch, they say; no 747s being built by hurricanes running through scrap yards. If you find a watch in the middle of a field, which is more likely: that it was assembled by accident, or it was constructed by an intelligent person and left there? You can’t create something out of nothing, and if something looks like it was designed then someone had to have designed it, right?
This argument by analogy mischaracterizes neo-darwinian evolution, but I’ll leave that for another day. For now, I’ll cover the infinite regression involved in the assumption that anything sufficiently complex has to have been the result of design by a creator.
First, I’m assuming that any creator must be at least as complex as that which it creates. Second, for the sake of argument, I’ll assume that all things in this world must have been created by an intelligent agent at some time or another, because their complexity leaves no other option. Again, this isn’t true, but it’s just for the sake of argument… you still with me?
So, we can — as Russell did — ask: who created the creator? If all complex things need a creator, and the creator is more complex than its creation, then there’s an infinite loop. We just keep pushing the problem back. If, however, we assume that the creator is the “first cause,” then we’ve traded the infinite regress problem for a different one. Consider the two possibilities in this scenario: the creator, who just exists (is outside of time, ultimately unknowable, etc, whatever excuse you want), created the universe; or, the universe just exists. Occam’s razor dictates that the simpler answer, the latter, is the correct one.
Intelligent design advocates love to point out that their so-called theory makes no claim about the creator, other than that “some intelligence is required” to explain complexity in life. I see them bring this up when asked how the existence of a creator is falsifiable — it isn’t, but they argue that it doesn’t matter. But, of course, there’s an implicit assumption that a creator exists in ID.
On what evidence do they base their conclusion that a creator exists? The only evidence ID supporters present is evidence of “design,” meaning examples of things that look “designed” to us, or that (so ID supporters say) can only be explained by design. But why is design evidence of a designer? Well, a designer has to exist, since the complexity in life can only be explained by the existence of a creator, as per my assumption above. More specifically, a creator more complex than its creation is required. Is it simpler to assume that a creator created the watch in the field, rather than it occurring through natural processes?
They’re right about the watch. It was intelligently designed — presumably by a human. But who created the creator of the watch? Is that an unfair question to ask? No, it’s a perfectly reasonable question to ask. Going by ID logic, that watchmaker in turn had to have been created. Evidence points to evolution by natural selection, of course, but in our thought experiment here we’re dealing with ID’s assumption that complex things have intelligent creators. So, who created the watchmaker? The creator, or intelligent agent they always refer to, I’d assume would be their answer.
But, as we’ve already gone two levels in, why stop here? Who created that creator? Is this an unfair question? Not any more than the previous two were. We had evidence to support the conclusion that the watch had an intelligent designer. ID supporters claim to have evidence concluding that there’s an intelligent designer for us. Why not go one level further? If there has to be intelligence for there to be complexity, and there has to be a creator if there is intelligence, and the creator is more complex than its creation, how do we escape the infinite loop?
“Suppose we change the subject,” they say.
