Thoughts on the Fine Tuning Argument


In recent years, I have tried not to devote too much time to debating with Christians online as I find it quickly spirals out of control for me. I really enjoy the challenge of these arguments, of striving for a better understanding not only of the views of others, but also the elucidation of my own views that I find this practice brings with it. After all, you never truly know where you stand sometimes unless you but heads with someone else who has a different point of view.

Recently however I have noticed a bunch of posts regarding the ‘Fine Tuning’ argument for a creator god appearing on my Facebook feed and elsewhere. This had always struck me as a particularly weak and unfounded argument, so I wrote the below reply to a Christian friend and wanted to share it here (if only to simply get it off my chest).

What the hell is fine tuning anyway?


Pictured: the universe (or part of it)


For those not familiar with the argument, the basic idea is that the physical constants that make life possible in our universe, whether it be the gravitational constant, the ratio of the strength of electromagnetism to the strength of gravity, the cosmological constant, etcetera, are so finely tuned to their particular value, that this speaks to the existence of a divine tuner, who has set the universe’s properties up accordingly. So for instance, if the gravitational constant wasn’t exactly what it was, the formation of planets might not have been possible.

Why I think this is a weak argument.

The problem with the fine-tuning argument is that it presupposes that these constants are something that has to be tuned to begin with.

To claim that a constant has to be fine tuned, and that there are other possibilities as to how the world could have turned out, is to confuse the idea of a constant, with that of a variable. Take a circle as an example. You can finely tune its radius to produce whatever area you want, but the value of pi is a constant, and thus beyond your tuning abilities to alter the nature of the circle.

The fine-tuning argument really just seems to be the anthropic principle dressed up in different clothes and paraded into the conversation.

The best way I can think to try and understand how these constants are most likely something that isn’t even ‘tunable’ is to consider other constants of our reality, namely mathematical constants. I believe this is an apt comparison to make, especially given the deep link between the mathematical world, and the physical one.

Consider Pi


Fun fact: I named my Chihuahua Pi, and he is predictably irrational


Let’s go back and consider for instance the number pi, the ratio of the circumference of a circle to its diameter; has this constant been finely tuned? If the value of pi were changed in any way, then circles would no longer exist, along with any other number of mathematical constructs, and the physical realities they are linked with. So, is the value of pi one of these finely tuned constants that creationists often refer to?

I have never heard people claim that the value of pi must have been finely tuned. I think this is because the number is considered an intrinsic property of circles, and that if the number were changed, or defined in any other way, then the thing it is related to would cease to exist.

Now consider the rest.

Extending this to the physical constants of our universe, is it really that far-fetched to suppose that these constants are a fundamental property of our own universe, and that the reason they are constant, is because they are an intrinsic part of how the universe exists? Creationists may like to imagine a god fiddling with the knobs and fine tuning a universe, but if the value of these constants is restricted by the very nature of the universe (like how pi is linked to the nature of a circle), then suddenly the idea of any tuning become impossible.

You might argue that some of the constants being referred to could conceivably be tuned to some other value while still allowing a universe to exist, albeit one that simply doesn’t allow the formation of a universe able to sustain life as we know it today. But given that we don’t know the entire nature of how these constants interact, or how they function, to suppose that some of the constants have ‘possible ranges’ that they could be set to, is not something supported by any facts. It is not, after all, as if we have any other universes with differently set constants which we can compare these to.

Maybe if these gods had created a parallel universe with a weaker strong nuclear force, or a stronger weak nuclear force, we would be able to peer across the boundaries of our own and observe such a thing. But this simply is not the case.


In my opinion, the fine tuning argument is a weak argument because it presupposes the mechanism of fine-tuning, and then uses this contentious idea to support itself. There is no evidence of tuning being something that is possible, any more than we can imagine the number pi being changed by a god during its act of creation.

What do you all think?