General Theism (Part 3): Fine-Tuning

For our second argument in favor of God’s existence, we’ll need to lay some mathematical and scientific groundwork. Bear with me – this argument is quantifiably powerful in a really unique way, so I promise the numbers pay off.

Most of us probably learned the equation for gravity in high school: F = \frac{G m_1 m_2}{r^2}

In that equation, F is the force of gravity, m_1 and m_2 are the masses of the two objects on which gravity is acting, and r is the distance between the masses. G, though, is just a number – 6.67408 × 10-11 m3 kg-1 s-2, to be exact. And G isn’t alone – we find constants like this throughout the most foundational equations in physics. These constants don’t seem to be determined by the laws themselves or (generally) by one another – mathematically, many combinations of values for these constants would produce a consistent description of a universe.

It was typically assumed that the values of these constants could have fallen anywhere within a wide range of possibilities without any substantial consequences for the universe; this idea is now near-universally rejected by theoretical physicists. It turns out that an inconceivably small number of the possible combinations of these values produce a universe permitting life – physicists call this phenomenon “fine-tuning.” There are many examples of fine-tuning, but to examine one of the more understandable ones, let’s think about stars. We take it for granted that the universe is filled with interesting elements from which life is made – oxygen, carbon, iron, nitrogen, and so on. But immediately after the Big Bang, the universe contained only hydrogen, helium, and trace amounts of lithium and beryllium; those ingredients aren’t sufficient to produce the chemical complexity needed for life of any kind. Heavier elements had to be formed through billions of years of nuclear fusion in stars – but what if stars didn’t exist? As outlandish as that may sound, stars depend on a delicate balance of gravity and the strong nuclear force to sustain themselves – in fact, if you were to pick a random gravitational constant and coupling constant (which determines the strength of the strong nuclear force), the odds that you’d pick one that permits stars is just 1 out of 1035! Without stable stars there’s no way of producing heavier elements and hence the chemical complexity needed for life to exist. (This example was selected for clarity rather than strength; for any sciency readers wanting more data, you can check out the work of Luke Barnes in his book “A Fortunate Universe: Life in a Finely Tuned Cosmos” or his research papers such as this one:

The question, then, is how are we to explain this fine-tuning? We can divide explanations of the fine-tuning of the universe into three basic categories:

  1. Fine-tuning is the result of design.
  2. Fine-tuning is the result of necessity.
  3. Fine-tuning is the result of chance.

I define these terms so as to make the groupings exhaustive: “design” means that the fine-tuning of the universe was purposefully causally influenced by a personal being, “necessity” means that the universe wasn’t designed and could not have different from the way it is, and “chance” means that the universe wasn’t designed and could have been different, i.e. it just happened to be the way that it is.

How do these explanations fare? Design does pretty well – if there were a transcendent person, it’s pretty plausible (or at least not wildly implausible) that they’d be interested in creating a universe in which other persons could come to exist. Let’s turn to the other two.

The explanation of physical necessity proposes that our marvel at fine-tuning is like a 2-D creature marveling at the fact that the angles of the triangle in which he lives add up to exactly 180 degrees – but of course it shouldn’t be that surprising, since the angles of a triangle must add up to 180. But the proposal that, like the triangle, our universe had to be this way is worse than speculative – a wide range of constants do appear to be compatible with the laws of our universe, and far from having evidence to overwhelm this appearance, the variability of constants is implied by the Standard Model as well as even its more speculative competitors (including String Theory). There’s just no good reason to believe that the values of the constants are necessary – it’s sheer wishful thinking.

The “explanation” of chance simply acknowledges fine-tuning and asserts that we got really really (really really really) lucky. And while this is certainly possible, rational thinkers seek to avoid excessive improbability. If a bank robber entered the 12-digit vault code in a single try, it’s possible that he guessed it, but overwhelmingly more likely that he already knew it (e.g. from a corrupt bank employee) – any good detective would move forward with the latter as their working theory over the former. So unless we have prior evidence making the design hypothesis as unlikely as fine-tuning by chance (on the order of 10-35 from just my one example), design is the way we ought to go.

As with all our arguments, the Fine-Tuning Argument doesn’t produce certainty in its conclusion that a cosmic designer exists, just rational confidence. Furthermore, the Fine-Tuning Argument in isolation doesn’t even tell us that the designer is God – for instance, the theory that our universe is a computer simulation could also explain the fine-tuning via a design hypothesis. But just as learning that someone is at the door makes it more likely that any particular person is, our confidence in there being some cosmic designer should likewise make it more plausible that a particular cosmic designer (God) exists.


General Theism (Part 2): The Kalam Cosmological Argument

We’ll be starting our “debate” on General Theism with the affirmative side; what are some reasons we ought to believe that God exists (or at least that He plausibly might exist)? Before I begin, I’ll note that there are innumerably many reasons why theists actually believe that God exists and I’ll readily concede that many of them aren’t good; however, the existence of bad arguments for a thing doesn’t imply that there aren’t also good ones. I’ll also note that I’m not claiming to know with certainty that God exists – I don’t even know with certainty that my apartment exists. My contention is merely that these arguments, taken together, make it more plausible that God exists than that He doesn’t.

The first argument in my cumulative case is called the Kalam Cosmological Argument. My presentation of it will be closely based on the work of Dr. William Lane Craig, an excellent philosopher/theologian/apologist who’s defended this argument in great depth. (He’s also the founder of Reasonable Faith, of which we are a chapter.) I’ll be giving a very light version of the argument aimed at comprehension; if you’re interested in a heavier treatment of it, you can check out Dr. Craig’s work at

The argument runs like this:

  1. Everything that begins to exist has a cause.
  2. The universe began to exist.
  3. Therefore, the universe has a cause.

This is a deductive argument, meaning that it has a set of premises (statements 1 & 2) which together imply a conclusion (statement 3). You cannot rationally believe that 1 and 2 are true but 3 is false. Hence, all the defender of this argument needs to do is defend the truth of its two premises.

So why believe premise 1, which states that everything that begins to exist has a cause? A few reasons can be given in support of this pretty intuitive principle. For starters, we observe no exceptions to this rule in the collective scientific and day-to-day experience of humanity, so it’s reasonable to inductively infer that the principle holds in general (rather than that things do begin to exist without causes, but coincidentally only when our back is turned). Furthermore, suppose for a moment that something (say, a universe) could causelessly begin to exist; what’s stopping a universe from causelessly beginning to exist in front of me right now? (Or now? Or now?) It seems that someone who rejects this premise would have to say “nothing” – there is absolutely no reason why a universe couldn’t appear in front of me right now and incinerate me in the second Big Bang. It seems extremely implausible that universes can causelessly begin to exist but have, for no reason whatsoever, only done so once.

What about premise 2 – why believe that the universe began to exist? (Note that by “the universe,” I’m referring to all space, time, matter, and energy – this is a relatively standard definition.) We have good reason, both philosophically and scientifically, for thinking that it did. Philosophically, an infinite number of past events is absurd, since we’d have had to traverse an actually infinite amount of time to reach the present. (Think of why it’s impossible for someone to count from negative infinity to 0.) It would seem that there must be finitely many past days (for instance) – but this implies an absolute beginning. Scientifically, the Big Bang model explains what we see about the universe far better than any competing model, and it implies an absolute beginning of the universe (after which the model is named) about 13.8 billion years ago. One would have to reject both of these streams of evidence in order to deny this premise.

So if the first two premises turn out to be true, it follows logically that the universe has a cause. But nothing can cause itself (since it’d have to exist prior to its own existence), so if the universe (which is all space, time, matter, and energy) had a cause, that cause would have to be spaceless, timeless, and immaterial. We even have reason to suspect that it’s personal, but that requires heavier thinking than I want to do in this introductory post – if you’re curious, check out Dr. Craig’s treatment of the argument. But even without pressing for personality, the conclusion that the universe has a transcendent cause should help make the existence of God more plausible.

As I stated up front, I’m not claiming that this argument gives us certainty that God exists, and I don’t even require that it gives us a high degree of confidence that He does. I’ll be making a cumulative case for God’s existence, so we’ll be examining several different lines of evidence; even if no one of them is strong enough to demonstrate God’s existence on its own, I claim that they succeed when taken together. But even before seeing those other arguments, the Kalam should make you pause and think – are you willing to deny either premise in order to escape the conclusion, and if so, why? Be sure to share you thoughts and comments below!


General Theism (Part 1): Intro

Imagine you’re at home watching Netflix, playing computer, reading a good book, or whatever it is you do in your free time. You receive a call from a trusted friend, and as soon as you answer, they immediately yell “You’re never gonna believe it, I just saw _____!”

I contend that your response to your friend’s exclamation will depend substantially on what it is they claim to have seen. If, for instance, it’s “a live T-Rex rampaging through New York,” you’re immediately going to suspect that they’re joking or hallucinating. If it’s instead “Tom Cruise walking down the street,” you may be a bit suspicious but willing to believe them after further questioning (are you serious? are you sure it wasn’t just a look-alike?). If it’s “a really cute cat,” you’ll probably just take them at their word.

In each case, you have the same “immediate” reason for believing that your friend saw the object in question: their testimony. The difference between your responses is due, then, to a priori beliefs that you have about live T-Rex’s (there are none), Tom Cruise (he surely walks down streets sometimes), and cute cats (they’re everywhere because cats are adorable, change my mind).

Similarly, when assessing the question of whether the Christian God exists, our response to the “immediate evidence” for Christianity’s truth will be shaped by the background knowledge we bring to the table. (Note that by the above analogy I am not implying that belief in Christianity amounts to taking someone’s word for it. All I mean to say is that whatever kind of evidence we’re looking at, our prior knowledge will affect our interpretation of it.)

So what kind of an attitude should we have about God before we even see the evidence for Christianity? Is He more like a live T-Rex, Tom Cruise, or a cat? By assessing arguments for and objections to “general theism,” or belief in a monotheistic God of any kind, we can better determine how skeptical we should be of any particular person or group who claims to be revealing Him to us.


One True Religion?

Welcome to our first official blog post! We here at Reasonable Faith UTD hope that this blog can serve as a forum for civil and rational discussion of the evidence and objections pertaining to God, Christianity, and Christianity’s many alternatives. But to go ahead and lay our cards on the table, we think that Christianity is true in a way that no other religion (or even more broadly, worldview) is.

To some of you, that claim may seem ridiculous because you’re confident that Christianity is false and any sincere investigation of the facts will show that to be the case. I’m so glad you’re here, and we have much to discuss! But I want to begin even further back in the discussion; to some people, the claim that Christianity is true may seem ridiculous because “true” isn’t the kind of thing that a religion can be (or fail to be). They may regard religion as more like a preference in the same category as which football team you support or which flavor of ice cream you eat. If that’s you, I’d like to challenge you in this post to reconsider what religion really is.

The fact is that all religions make claims about the way the world is and will be. Even in just the major world religions, there’s a remarkable degree of factual divergence. Buddhism doesn’t hold that there’s a personal God, Islam holds that Allah is one person, Christianity holds that God is tripersonal, and Hinduism is somewhat ambiguous on the subject. After you die, Buddhism and Hinduism hold that you will be reincarnated until you eventually escape the cycle and cease to exist as an individual, Islam holds that Allah will judge you and salvation can be found in Allah’s mercy which He will dispense to the righteous, and Christianity holds that God will judge you and salvation can be obtained only by faith in Jesus. I hope it’s evident that these assertions can’t all be true.

“Okay,” you may concede, “religions present pictures of reality that contradict each other. But aren’t religions really just about how to be a good person? After all, that’s where the rubber really hits the road – all this ‘God’ and ‘afterlife’ stuff is just peripheral.” And indeed, it is true that some of the external behaviors of different religions are similar, such as loving others and attending regular religious services and so on. But I’d argue that while these things are definitely important, they are the more peripheral parts of a religion in the sense that they’re based on and derived from the religion’s factual view of reality, not the other way around. The Bible says in 1 Corinthians 15:17-19 that “if [Jesus] Christ has not been raised [from the dead], your faith is futile … [and] we are of all people to be most pitied.” Here, Paul (who wrote 1 Corinthians) is staking the value of Christianity on the factual issue of whether or not Jesus rose from the dead; if He didn’t, Paul says that Christianity is a waste of time and Christians are pitiful. (For those unfamiliar with the Bible, Paul doesn’t mince words.)

In short, if we want to know how the world ought to be, it seems we first need to understand how it actually is. Is there really a God who created the universe? If so, what is He like? And was Jesus of Nazareth actually raised from the dead? Our answers to these questions will powerfully influence, and perhaps determine, our answers to many others. Let’s investigate!