A very smart man once wrote a very stupid thing in a book.His name was Douglas Adams, and the book was his posthumously published The Salmon of Doubt: Hitchhiking the Galaxy One Last Time (New York: Ballantine, 2002; pages 131-132). Adams died of a heart attack in Santa Barbara in May 2001; he was only 49. I’m a longtime fan of Douglas Adams and his Hitchhiker’s Guide to the Galaxy series. But in this instance, Adams’ analogy—known as The Puddle Analogy—is far less profound than he supposed.
Adams’ Puddle Analogy has been cited many times by various writers as a satirical demonstration of the “fallacy” of the “fine-tuned universe” argument. The Wikipedia article “Fine-Tuned Universe” quotes the Puddle Analogy and notes that the fine-tuned universe argument has been called “puddle thinking” by some critics. Richard Dawkins quotes The Puddle Analogy in A Devil’s Chaplain: Reflections on Hope, Lies, Science, and Love (page 169), adding that he had heard the Adams analogy numerous times and “thought it was more brilliant every time.”
Here is the stupid thing Douglas Adams wrote:
Imagine a puddle waking up one morning and thinking, “This is an interesting world I find myself in, an interesting hole I find myself in, fits me rather neatly, doesn’t it? In fact it fits me staggeringly well, must have been made to have me in it!” This is such a powerful idea that as the sun rises in the sky and the air heats up and as, gradually, the puddle gets smaller and smaller, it’s still frantically hanging on to the notion that everything’s going to be alright, because this world was meant to have him in it, was built to have him in it; so the moment he disappears catches him rather by surprise. I think this may be something we need to be on the watch out for.
Here’s why The Puddle Analogy is stupid:
Adams begins: “Imagine a puddle waking up one morning and thinking…” He doesn’t seem to realize that, in order for a puddle to wake up and think its first thought, a vast number of interconnected and incredibly unlikely coincidences have to occur.
The Big Bang had to happen, and the Big Bang had to explode with just the right amount of force to allow matter to disperse evenly and smoothly and allow galaxies to form. Had the Big Bang not been precisely fine-tuned, our universe might consist of nothing but tenuous hydrogen gas—or a single supermassive black hole. The laws of nature had to be laid down at the instant of the Big Bang, and had to be fine-tuned to an accuracy of one part in the trillions before the universe itself could exist, much less a contemplative puddle.
The electromagnetic force, the gravitational force, the strong nuclear force, and the weak nuclear force all had to be perfectly balanced in order for stars to form and begin cooking up the elements needed to make planets—silicon, nickel, iron, oxygen, magnesium, and so forth. Adams’ pensive puddle could not find itself sitting in “an interesting hole” unless the hole was situated on a planet orbiting a star that was part of a galaxy that was created by the incredibly fine-tuned forces and conditions of the Big Bang.
And in order for that puddle to wake up one morning and think at all, it would need to be a lot more complex than a mere puddle of water. A thinking puddle would be a very complex puddle indeed. Even if that puddle were comprised of exotic alien nerve cells suspended in a matrix of liquid ammonia, it would certainly need something like lipid molecules and protein structures and nucleic acids in order to become sufficiently evolved as to wake up and contemplate its own existence.
Such components require the existence of carbon. And if you know anything about where carbon comes from, you know that carbon doesn’t grow on trees. It is formed in an amazingly fine-tuned process involving the precise placement of a nuclear resonance level in a beryllium atom. Any enlightened plashet would have to conclude that a superintellect had monkeyed with physics, chemistry, and the biological composition of pools and puddles.
The rest of Douglas Adams’ scenario, in which “the sun rises in the sky and the air heats up and … the puddle gets smaller and smaller” is meaningless in view of the fact that thousands of events, forces, and conditions have to interact in a fine-tuned way in order for the sun to exist, the air to exist, the sky to exist, and the hole in the ground to exist, so that a puddle can wake up one morning and wonder about its place in the cosmic order.
No analogy is perfect, of course, but The Puddle Analogy is downright misleading. It misrepresents the essence of the fine-tuning argument. An analogy should simplify, but not over-simplify.
And that’s why The Puddle Analogy that Richard Dawkins thinks is so brilliant is actually incredibly dumb.