Is belief in God rational?
That is the question I brought up with my seventh grader last year as we read together Martin Rees’s Just Six Numbers: The Deep Forces That Shape the Universe (Basic Books, 2000). We actually just read the introduction together as a supplement to his science textbook. Although the introduction is only a few pages long, it provided a good summary of the book and made the point I was trying to make: Yes, belief in God is entirely rational.
Belief in God:
According to the apostle Paul, people know that God exists and are therefore without excuse when they “suppress the truth in unrighteousness” (Romans 1:18-19, ESV). Paul writes, “For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.” (Romans 1:19-20, ESV).
In line with scriptural teaching, French Reformer John Calvin (1509-1564) wrote of a “sensus divinitatis” (sense of divinity) in all people. In Institutes of the Christian Religion, he argues that, “There is within the human mind, and indeed by natural instinct, an awareness of divinity. This we take to be beyond controversy. To prevent anyone from taking refuge in the pretense of ignorance, God himself has implanted in all men a certain understanding of his divine majesty.” (Book 1, Chapter III, Sec. 1).
If belief in God is implanted in us by God himself, then what is the purpose of rational arguments for God’s existence? The idea I wanted to pass on to my son was that although our belief in God and in his revelation in the Bible are not ultimately rooted in rational arguments, they nonetheless can be rationally supported.
Martin Rees’s Just Six Numbers: The Deep Forces That Shape the Universe is an poignant example from science.
Just Six Numbers:
Martin Rees, a cosmologist and astrophysicist, is Royal Society Research Professor at Cambridge University and holds the title of Astronomer Royal. According to his biography on the back cover of the book, he is an international leader in cosmology. Some of his other works include Gravity’s Fatal Attraction: Black Holes in the Universe and Before the Beginning: Our Universe and Others.
In Just Six Numbers, Rees discusses six significant numbers identified by theorists that “constitute a ‘recipe’ for a universe,” which make life in our universe possible (p. 4). He argues that “if any one of them were to be ‘untuned’, there would be no stars and no life.” (p. 4). I don’t presume to fully understand the following numbers (I am not a cosmologist or an astrophysicist), but his overall argument is nonetheless compelling:
1. The large number N:
“The cosmos is so vast because there is one crucially important huge number N in nature, equal to 1,000,000,000,000,000,000,000,000,000,000,000,000. This number measures the strength of the electrical forces that hold atoms together, divided by the force of gravity between them. If N had a few less zeros, only a short-lived miniature universe would exist: no creatures could grow larger than insects, and there would be no time for biological evolution.”
2. The number Ɛ:
“Another number, Ɛ, whose value is 0.007, defines how firmly atomic nuclei bind together and how all the atoms on Earth were made. Its value controls the power from the Sun and, more sensitively, how stars transmute hydrogen into all the atoms of the periodic table. Carbon and oxygen are common, whereas gold and uranium are rare, because of what happens in the stars. If Ɛ were 0.006 or 0.008, we could not exist.”
3. The cosmic number Ω (omega):
“The cosmic number Ω (omega) measures the amount of material in our universe—galaxies, diffuse gas, and ‘dark matter’. Ω tells us the relative importance of gravity and expansion energy in the universe. If this ratio were too high relative to a particular ‘critical’ value, the universe would have collapsed long ago; had it been too low, no galaxies or stars would have formed. The initial expansion speed seems to have been finely tuned.”
4. The cosmic “antigravity” λ (lambda):
λ “controls the expansion of our universe, even though it has no discernible effect on scales less than a billion light-years. . . . Fortunately for us (and very surprisingly to theorists), λ is very small. Otherwise its effect would have stopped galaxies and stars from forming, and cosmic evolution would have been stifled before it could even begin.”
5. The number Q:
“The fabric of our universe depends on one number, Q, which represents the ratio of two fundamental energies and is about 1/100,000 in value. If Q were even smaller, the universe would be inert and structureless; if Q were much larger, it would be a violent place, in which no stars or solar systems could survive, dominated by vast black holes.”
6. Our three spatial dimensions, D:
“Life couldn’t exist if D were two or four. Time is a fourth dimension, but distinctively different from the others in that it has a built-in arrow: we ‘move’ only towards the future.”
If not for his references to evolution, you might expect Rees to be a theist arguing for God’s existence by pointing out what seems to be a fine-tuning of the universe. However, he is an atheist. So how does he explain these numbers?
He appeals to a “multiverse” concept, which he admits is speculative (p. 13). He proposes that beyond our observable universe there might be “an infinity of other universes” where these six numbers may be different (p. 4), with different “physical laws and geometry” (p. 13). He proposes that we exist because we “emerged (and therefore we naturally now find ourselves) in a universe with the ‘right’ combination.” (p. 4). In other words, from among the infinite number of universes with different physical laws, we exist because we happen to find ourselves in the right universe where life is possible.
So what?
As my son and I discussed Rees’s book, we obviously found ourselves disagreeing with his conclusion. However, his book (even just his introduction) allowed me to highlight three points for my son. First, theists are not the only ones who recognize that the universe seems finely-tuned to allow for life. Rees, a cosmologist and physicist who denies the existence of God, also recognizes the apparent fine-tuning of the universe. He wrote an entire book about it. Second, those who deny God’s existence must go to great lengths to explain away the apparent fine-tuning. Rees had to speculate the existence of an infinite number of universes beyond our observable universe, each with its own combination of physical laws. Finally, belief in a Creator who fine tuned the physical laws of the universe to allow for life is entirely rational and supported by scientific evidence as presented by Martin Rees in Just Six Numbers.
As we finished our discussion, I reminded my seventh grader that although our belief in God and in his revelation in the Bible are not ultimately rooted in rational arguments, they nonetheless can be rationally supported. Martin Rees’s Just Six Numbers is a poignant example that reminds us of that truth.
Soli Deo Gloria
W. Michael Clark, Ph.D., J.D.
Founder, Golden Oak Society
