Finely-Tuning the Fine-Tuning Argument

If we were just a couple inches closer to the sun, we’d burn!!! Isn’t that scary? Unfortunately, this is how the Fine-Tuning Argument is presented on a popular level[1], and it reduces the argument and makes it easy to refute. An NBA basketball player not combusting when they dunk a ball would be such an example. However, the actual fine-tuning argument is one of the best arguments a Christian apologist can use, so it is important that we do understand it.


The Fine-Tuning argument doesn’t assert that if we were a wee bit closer to the sun, we’d burn, this was pointed out recently by Christian Apologist Richard Bushey:

Typically when scientists convert to theism, they find the fine-tuning argument the most compelling. Of course, these esteemed scientists are not citing a bastardized version of the argument that is typically paraded. Hack apologists might say something like, “If the sun were just one inch closer, life would not exist”

The obvious rebuttal to this argument is to just tell them to jump in the air and see if they are incinerated. The most sophisticated treatment would be best described by William Lane Craig

By “fine-tuning” one does not mean “designed” but simply that the fundamental constants and quantities of nature fall into an exquisitely narrow range of values which render our universe life-permitting. Were these constants and quantities to be altered by even a hair’s breadth, the delicate balance would be upset and life could not exist.[3]

But as you will see, not only are some arguments for fine-tuning bad but some of the objections as well.

Badly-Tuned Objections

“No Design Here”

 fine-tuning is not an argument for design, but rather an argument against design! The idea of an extreme fine-tuning beyond which the target cannot exist is indicative of a precarious natural system, not of intelligent planning.

To understand this, an analogy may be useful. Suppose that our breathing was dependent on a specific level of oxygen in the atmosphere, and that any other level would cause suffocation. That would certainly count as “fine-tuning” in the sense given by the argument. The atmospheric composition in question would be the only one capable of supporting life, and this would therefore demand “explanation”.

But even if that was true, how would this fine-tuning justify design explanations? A designer would not make it so that humans would constantly face the danger of suffocation! An intelligent designer would try, whether possible, to ensure that a given system could keep functioning under different conditions. Such is the case with humans, who can breathe in atmospheres thin or rich in oxygen. The precarity of a system’s functioning is not evidence of design, but rather of natural law.[4]

This objection is exactly the type that William Lane Craig was addressing above. From Fine-tuning we are not arguing design in a direct sense but in a probabilistic cumulative sense. The last paragraph is nonsensical, an arbitrary “what I think an Intelligent designer would do” is not an argument.

“Many Worlds”

Possible world language though around since at least Leibniz has seen pioneers take the idea even further into development. David Lewis was one of those pioneers. Lewis developed a type of modal logic called “Possible world Modality”. Lewis also affirmed Modal Realism, which is the idea that all possible worlds are as real as the actual world. This would indeed change our view of probability and necessity, ultimately undermining the fine-tuning argument. However, there are several problems with this view and even Non-Christian philosophers object to it.

Are you familiar with the board game Candyland? I used to love that game as a kid. Well, thanks to Lewis, Candy Land is real. Since it is logically possible for a man to be named Lord Licorice who just happens to own a very lucrative licorice business, it seems as if Candyland is a feasible world. That’s the problem. Lewis is not saying that merely they exist as abstract objects in a platonic sense, but that they’re as real as the actual world.  This would be to say, in summation that all possible worlds are concrete.

Even if we grant that Lewis’s hypothesis is true, it wouldn’t be much to the fine-tuning argument. Because the possible worlds only deal with what is logically possible. The constants that bring the condition of life-sustainment wouldn’t be able to change, thus when it comes to constants, you either have human beings on the earth (This world) or you have some sort of other species that could live in a different set-up or none at all. This still makes the idea that the constants are so exact improbable, giving the appearance of design.

“What about the other Planets?”[5]

Most places in the universe will kill life instantly—instantly! People say “Oh, the forces of nature are just right for life.” Excuse me. Just look at the volume of the universe where you can’t live. You will die instantly.” (Often attributed to Neil Degrasse Tyson, though I couldn’t find the original source, though this site defends this quote approvingly as a good point.)


This objection is rather strange, especially coming from a very intelligent scientist. It’s a red herring at best, it is not like humans are being born and instantly dying on Mars. We think the other planets, at least in our solar system are not life-permitting, which is why it is so strange that Earth is. His objection actually strengthens our argument, most places are not suited for life, making it improbable that Earth should be.


Christians need to better understand the fine-tuning argument to prevent these misunderstandings. I will sum up this post with a logical syllogism by Dr. William Lane Craig

1: The Fine Tuning Of The Universe is due to either physical necessity, chance or design.

2: It is not due to physical necessity or chance.

3: Therefore, it is due to design.[6]


[1] Carman – There is a God
[2] God On Trial: Reviewing the best objections to apologetics by Richard Bushey
[3] Design from Fine-Tuning Q&A, William Lane Craig,
[4] StrongAtheism.Net “The many problems of the fine-tuning Argument” by Francois Tremblay
[5]“William Lane Craig’s silly response to the hostility of life” by Jeffrey Jay Lowder
[6] Reasonable Faith: Christian Truth and Apologetics by William Lane Craig p. 161

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