Twitter with @AbuAbdallahF #2 : Fine-tuning, the puddle fallacy and the anthropic principle
This post is number two in a series, so if you’re missing context you might want to check out this post first.
So, let’s start out with the most intuitive part of my answer to him, which is his claim that the natural world is evidence enough for the existence of a creator. Here is the relevant excerpt of his statement:
“Regarding the evidence of the existence of the Creator. For me personally, the entire universe, which functions based on natural laws, systems, the sun, the moon, water, plants, animals, this is more than enough evidence. If that doesn’t satisfy you…well, that’s still your own problem. If you examine these natural laws you will notice that their sole direction and purpose is allowing us to live. One single alteration and everything will go BOOM! Our bodies with their different systems, each system containing organs, each organ containing components…do you realize that we are machines controlled by information? We are much more sophisticated than any machine man has ever created.”
The first part is a version of the prevalent argument you’ll often hear from christian apologists as well. It’s called the fine-tuning argument for god. The second part addressing our bodies is no evidence of anything, because the complexities can easily be explained by the process of evolution by natural selection. I’ll leave evolution out here, because I’d like to devote at least one whole post to it; the topic deserves a little more than just a paragraph. This post is already going to be long anyways.
The fine-tuning argument for god goes something like this: “There are many natural constants so that, for each one, if it were a little different, we wouldn’t exist. Thus, it is extremely likely that these constants were set/tuned by a creator to allow for us to exist, because the probability for potentially completely random constants being at those values is small. Therefore, god exists.”
The same argument is often made for the universe and/or life in general instead of humans, especially by theists and deists that accept evolution, and thus know that our existence within a universe with life can be explained by it. Logically, the argument has the same structure, though.
There are many problems with this argument, so I’ll touch on a few of them.
The most obvious and striking flaw in the argument, or at least the way it is commonly used, is the implicit fallacy of equivocation in its conclusion: the use of the word “god”. All the argument aims to show is the existence of a cause that is powerful enough to influence these constants and cares enough to adjust them so we can exist. The word god, in its theistic sense, describes a being that has many more attributes. Additionally, these change from religion to religion. This fact alone makes the argument alone completely useless for any kind of theistic viewpoint except “god is a being that created the universe and adjusted constants so we could come to exist” without further assertions about this being.
The fine-tuning argument also commits the rather cutely named ‘puddle fallacy’, a term coined by Douglas Adams. Here is his analogy that aims to satirize the way people using this argument think:
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 all right, 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.
The argument shining through the satire is that the situation we find ourselves in is exactly what we would expect from a precarious natural system. The only thing that’s necessary to make sense of this objection is that a natural system shapes its content without a mind necessary behind it, because it doesn’t allow for things its properties don’t permit. Understanding this principle is also a big help when trying to understand evolution, which I will address in a later post.
A misconception about probabilities ties into this as well. Imagine a fair dice roll with a die with a billion sides. Let’s say the result of the roll is 35,226,192. Well, what is the probability for that to happen? It’s one in a billion. Yet, for any sensible observer the result is nothing to be astonished about. One of the sides had to come up, each with a probability of one in a billion. You wouldn’t assume that someone willfully turned the die to this side, would you? Saying that would be willfully ignoring data, namely, that the die has already landed at that side. This leads me to the anthropic principle.
3. The Weak Anthropic Principle
Let me preface this by saying that I am now, to a large extent, leaving the domain of science and entering the realm of philosophy. The anthropic principle alone also does not refute the idea of a creator in general; it only shows that one of the implications in the argument is false, as further explained in 4. .
The (weak) anthropic principle is a remarkably simple yet prominent philosophic consideration regarding such constants. It is not needed to debunk the fine-tuning argument, but interesting nonetheless. Its structure is one or another version of the following (read the original definition on the Wikipedia page linked at the start of this paragraph):
a) Premise: We can only observe if we exist
b) Premise: We can only exist if natural constants allow us to exist
c) Premise: We observe
d) Conclusion: Natural constants must allow us to exist
In simple words: if natural constants wouldn’t allow for us to be in this universe, we couldn’t be here to observe it. Thus it is completely unremarkable that those constants fall exactly into the spectrum that permits life. It entertains the idea that the constants being the way they are is nothing more than selection bias.
To make selection bias clear, consider an exemplary game with the following rules: you roll a standard fair die. If it rolls on a 6, you get a million dollars. If it rolls on any other number, though, you and everything around you is instantly destroyed. Now, if you roll the die, given that you do observe, how surprised are you really to see a 6 when you look down? Hopefully not a whole lot. You wouldn’t be there to observe it if you had rolled any other number. The probability for observing a 6 given that you do observe is 100%.
We are in the same situation. It is empirically certain we observe, so it shouldn’t come as a surprise that our universe around us permits us to. Claiming the universe could be any other way is ignoring data that we have, namely: that we are here.
The anthropic principle alone is not enough to prove the idea of a creator to be impossible because for selection bias to occur, there must be a selection. It thus draws on one or the other form of the multiverse, which is itself merely a hypothesis, which is, depending on its various definitions, more often than not unfalsifiable. But the possibility alone leads me to my final objection:
4. Disregarding Possibilities
At its base, the fine-tuning argument for god lacks a necessary premise that, if stated, wouldn’t be able to be supported. The flaw lies in the argument “The probability for potentially completely random constants being so is small means it’s very likely that there is a creator”. This would only follow if there was an additional premise like “the only possibilities for the constants to be at those values are completely random or set by a creator”. This is, of course, not true. Note that, even if there is only one other possibility than a creator or complete randomness, the argument is flawed, so any alternative theory or even just a hypothesis debunks this argument. There are many alternative theories as to what forced these constants to be that way, so certainly more than one alternative possibility. A short list can be found here. A creator does not follow simply by the possibility that these values might not be uniformly random despite the lack of a designer. To rephrase again: it’s not clear that those constants could have taken on any values, so the probability them being within those values that permit our existence is unknown, not as people using this argument would state without proof “extremely high”.
Yet another way to say this is: just because different values for those constants are conceivable doesn’t make them possible. Those constants might interfere with the existence of the universe as a whole. Or they may just be impossible altogether for yet unknown reasons.
We lack empirical evidence as to where the universe came from. This means assumptions about the probabilities involved will always be baseless until demonstrated. And especially if you use a statement like “all conceivable values for natural constants are equally likely” as a premise to your already flawed argument, you’ll be called out on it.
For some further reading on this topic I might suggest the strongatheism library. It goes into much more detail than I’ve given here and also raises additional objections. I’ll tackle the topic of evolution next, because it is such an important base line for understanding our own existence withing the universe purely because of natural processes. If you are a creationist, the least you can gain from this is better understanding of a process you so frequently criticize.
As always, I’d be happy to hear criticism from anyone on tumblr or twitter, especially if I’ve inadvertently misrepresented any concepts presented here.