As our News Desk has noted, over at Mind Matters Michael Egnor engages with Jerry Coyne on whether, as a matter of logic, the cosmos can be self-existent. Egnor says no, and one reason he gives is the logical principle that any causal chain points to a first cause. He writes:
Imagine a chain hanging from the sky supporting a weight suspended in the air. Each link in the chain is a cause for the continued suspension of the links and the weight they hold up. However, the chain could not hold itself up alone. It can’t be “links all the way up.” Something at the beginning must be holding the chain up. And whatever holds the whole causal series up cannot just be another link in the chain. To be a “first cause,” whatever is holding up the chain must be something different from the chain itself.
Most of us are familiar with the amusing “turtles all the way down” story:
The following anecdote is told of William James. […] After a lecture on cosmology and the structure of the solar system, James was accosted by a little old lady.
“Your theory that the sun is the centre of the solar system, and the earth is a ball which rotates around it has a very convincing ring to it, Mr. James, but it’s wrong. I’ve got a better theory,” said the little old lady.
“And what is that, madam?” inquired James politely.
“That we live on a crust of earth which is on the back of a giant turtle.”
Not wishing to demolish this absurd little theory by bringing to bear the masses of scientific evidence he had at his command, James decided to gently dissuade his opponent by making her see some of the inadequacies of her position.
“If your theory is correct, madam,” he asked, “what does this turtle stand on?”
“You’re a very clever man, Mr. James, and that’s a very good question,” replied the little old lady, “but I have an answer to it. And it’s this: The first turtle stands on the back of a second, far larger, turtle, who stands directly under him.”
“But what does this second turtle stand on?” persisted James patiently.
To this, the little old lady crowed triumphantly,
“It’s no use, Mr. James—it’s turtles all the way down.”— J. R. Ross, Constraints on Variables in Syntax, 1967
Coyne would certainly howl in disdain and ridicule at the rube who believed in turtles all the way down. Isn’t it ironic, then, that he himself believes in a similar story except instead of “turtles all the way down” he believes in “links all the way up.”