A Brief Appraisal of the Fine-Tuning Argument

The fine-tuning argument is a popular argument for the existence of God, arising quite recently within the world of theism. The argument gained recognition primarily after advances in the sciences, particularly astrophysics and cosmology. Several modern apologists support the argument, including Robin Collins, John Polkinghorne, Richard Swineburg, William Lane Craig, and Alvin Plantinga.

According to supporters of the argument, certain fundamentals of the universe allow for intelligent life to arise. These laws, however, are so perfect that it’s improbable for them to naturally be this way. Rather, these key constants were likely adjusted by an intelligent mind, which proponents would say is God. This argument is somewhat unique because it’s primarily concerned with probability and scientific discoveries rather than metaphysics.

Advocates of the argument like to cite the laws of nature and certain constants of physics as key examples of fine-tuning. For example, gravity forces materials together within stars to generate heat, so without gravity, stars couldn’t form. Further, without gravity, planets and other large composite objects couldn’t form. Electromagnetism, on the other hand, holds electrons in orbit around their nucleus, which is absolutely fundamental to material complexity of any kind. Fine-tuning advocates also discuss constants of physics as indicators of fine-tuning. For example, the cosmological constant — as discovered by Albert Einstein — is quite important in General Relativity, especially in the expansion and contraction of the universe. Of course, these aren’t the only fundamentals of physical reality that advocates cite, but they should be enough for our short discussion.

While the above may seem abstract and hard to notice in our daily lives, supporters note that if some of those foundations were changed slightly, our universe wouldn’t be able to support complex life. These perfect conditions are incredibly unlikely to develop by chance, so there must be some sort of designer or tinkerer that’s greater than the Universe.


This argument has garnered significant controversy since it’s popularization by evangelists and apologists. New atheist philosopher and particle physicist Victor Stenger has been especially critical of the fine-tuning argument. He’s suggested that a “Monkey God” could have created the universe because some of the constants aren’t actually as important as supporters claim. He developed a computer program that randomly selected different constants for stars, showing that they could be altered and still allow the development of intelligent life. Robin Collins has responded to this criticism by arguing that Stenger’s simulation is too narrow. According to Collins, Stenger’s program oversimplifies the development of stars and entirely ignores other parts of the argument, so his objection fails.

Victor Stenger

Evolutionary biologist and new atheist philosopher Richard Dawkins stated the following in his (in)famous book The God Delusion:

“A designer God cannot be used to explain organized complexity because any God capable of designing anything would have to be complex enough to demand the same kind of explanation in his own right.”

This is an alteration of the classic “who created God?” question that was asked by David Hume, Bertrand Russell, and a flurry of atheists and agnostics since. Since this is a long discussion in its own right, we’ll only discuss the responses in the context of the fine-tuning argument. I will probably go into further detail when I examine certain classical arguments (St. Thomas, Scotus, Leibniz, etc.) and the Kalam Cosmological argument.

We can summarize Dawkins’ argument in the following way:

  1. Entities that are complex probably have a designer
  2. God is complex
  3. Therefore, God probably has a designer

It’s important to note, however, that Dawkins doesn’t actually agree with the first premise, but that he’s using it to show that we have to apply it to God. He’s trying to hold supporters to their own word, implying that they’d be using special pleading otherwise.

In my view, the second premise is absolutely incorrect. God is actually the most metaphysically simple entity to be, so there’s no reason for God to have a designer. Suggesting that God would have to be more complex than the universe to design it is odd since we can imagine a man who creates a computer far more complex than he, for example. Therefore, the second premise is plain wrong. However, apologists who deny divine simplicity certainly have a problem here.

Various critics of the fine-tuning argument suggest that we could simply be a lucky universe in the multiverse. Other universes may have other laws of nature and constants of physics, ultimately becoming utter chaos, but we happen to live in the lucky one.

There are several models of the multiverse, but the one that is likely the most dangerous for supporters of fine-tuning is Modal Realism, popularized by philosopher David Lewis. In this view, all possible worlds are real, so there are many universes just like ours that have intelligent life and other universes that are completely chaotic. Everything that could happen has happened in some universe, so fine-tuning exists in our universe because there has to be at least one universe like that.

The Multiverse in Modal Realism

While this view is certainly popular in science fiction, there’s very little evidence for it. However, there are plenty of other models like the inflationary multiverse, cosmic natural selection, and the brane multiverse (Ball). Collins argues that these views only push the problem back because the right conditions would have to exist in the multiverse in the first place.

Should We Use This Argument?

In my opinion, the fine-tuning argument is very weak compared to most others. This argument is based primarily on probability rather than necessity, which isn’t convincing to me. Since it’s based on probability, there’s very little it can do to establish the divine attributes. At most, it indicates that the Designer would be highly intelligent, skilled, powerful, and intentional. However, this doesn’t mean that the designer is God. I don’t see much in this argument — when used alone — that explains why the designer wouldn’t be super-aliens. Similarly, why monotheism? Why not deism or polytheism?

Fine-tuning also creates confusion in what God is. Assuming the designer is like God and not some aliens, it makes God look like a tinkerer rather than a wholly-unique entity. On its own, it really does nothing to make God any different from His creation.

Now, I admit that I am somewhat harsh here since I use different arguments to establish different divine attributes. For example, I often like to use the Aristotelian Cosmological Argument (also known as St. Thomas Aquinas’ “First Way”) to best establish God’s omnipotence while I use the Augustinian Proof of God to establish His omniscience. However, I do this because some arguments show some attributes better than others; it’s not that each argument can’t show the different aspects of God. For example, the Aristotelian Cosmological Argument can establish the following attributes of God on its own:

  • Omnipotence
  • Immutability
  • Eternality
  • Perfection
  • Absolute uniqueness/monotheism
  • Pure Goodness
  • Omniscience

The argument from fine-tuning also goes in the wrong direction based on complexity. The argument starts correctly, noting that our universe is complex and requires an explanation for that complexity. However, it clumsily tries to say that certain aspects of that complexity need to be adjusted to work properly. Instead, an argument from complexity should go to the metaphysical base found in simplicity.

Plotinus understood this, arguing that all complex substances require an ultimately simple substrate that holds them together. Therefore, regardless of whether the universe is utter chaos or blissful harmony, this ultimately simple entity must exist to uphold reality. This, of course, isn’t the full argument, but it’s a good primer. Even if the multiverse is real — in practically any model — Plotinus’ argument is entirely unaffected. With that in mind, while the fine-tuning argument may be attractive for some, it has hurdles that can be easily avoided.


The fine-tuning argument is far weaker than the traditional arguments. We need to focus on arguments that are based on metaphysical necessity rather than probability. While I wouldn’t recommend that we entirely ignore it, using the argument on its own isn’t valuable.

References and Further Reading

Ball, Philip. “Earth — Why There Might Be Many More Universes besides Our Own.” BBC, BBC, 21 Mar. 2016, www.bbc.com/earth/story/20160318-why-there-might-be-many-more-universes-besides-our-own.

Collins, Robin. “The Teleological Argument: An Exploration of the Fine-Tuning of the Universe.” The Blackwell Companion to Natural Theology, by William Lane. Craig and James Porter Moreland, Wiley-Blackwell, 2012, pp. 215–290.

Dawkins, Richard. The God Delusion. Bantam Press.

“Fine-Tuning.” Stanford Encyclopedia of Philosophy, Stanford University, 22 Aug. 2017, plato.stanford.edu/entries/fine-tuning/.

I usually post about philosophy and theology, but occasionally I’ll post about finance and economics. Overall, I’m just a Thomist who supports LCMS.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store