Jerry Coyne has posted in reply to my observation that God’s existence can be demonstrated by the ordinary methods of science. That is to say, all proofs of God’s existence are scientific theories in the sense that they have the same logical structure as any other scientific theory that proposes explanations for the natural world.
Scientific theories are inductive in that they depend upon evidence in the natural world to reach a conclusion. Thus demonstrations of God’s existence, for example Thomas Aquinas’s Five Ways, are scientific theories in the sense that Newton’s Law of Gravitation, Einstein’s Theory of Relativity, Quantum Mechanics, and Darwin’s Theory of Evolution are scientific theories. Scientific theories can demonstrate the existence of things outside of nature — the singularity that gave rise to the Big Bang and the singularities at the cores of black holes are things outside of nature. Science has demonstrated the existence of these supernatural singularities.
There is only one difference between the scientific demonstration of God’s existence and that of gravity, general relativity, quantum mechanics, or evolution: the evidence for God’s existence is immeasurably greater than the evidence for any other scientific theory.
Many readers will think this a radical statement but it is conventional natural theology. Natural theology is the branch of science that demonstrates the existence of God according to evidence in nature. It has deep roots going back at least to Aristotle. It is different from divine revelation, which is another way of understanding God.
Demonstrations of God’s existence in natural theology depend on evidence in nature, such as the existence of change, of causation, of a hierarchal manifestation of qualities, of teleology and design, and even of existence itself. For example, Aquinas’s First Way demonstrates God’s existence by showing the necessity for a Prime Mover to explain change in nature. That is, if everything that grows, moves, or changes in nature is caused to do so, a Prime Mover outside nature must start the causes. Thus, the evidence in favor of the First Way is observable in every movement of an atom, every gust of wind, and every physiological process in every organism. Everything and anything that changes in this world is a data point that supports the existence of God, according to Aquinas’s First Way.
As you might expect, atheists don’t like this fact. Coyne tries to offer rebuttals in his blog post. They serve mainly to demonstrate the fact that he doesn’t understand the problem.
One of Coyne’s commenters (Torbjörn Larsson) raised an issue worth noting — the claim that God is unnecessary because the universe itself may be the most fundamental thing that exists.
“Everything must have a cause. Therefore [magic agent].”
“What caused [magic agent]?”
“A [magic agent] need no cause.”
“Then there are things that need no cause. I cut out the middleman and can now say the universe need no cause.”
He is asserting that the universe itself is the ground of existence. God is unnecessary.
As philosophers have noted over the past several thousand years, there are many reasons why the universe cannot be the most fundamental thing that exists. I’ll discuss two of them here:
First, as Aquinas notes in his first Three Ways, change, cause, and existence in nature cannot go backward forever in an essential causal chain. “Essential” causal chains require the continued existence of all the causes in the chain. Forces and states in nature tend to be essential causal chains — the warming of the air in summer is due to the direct radiance from the sun due to tilt of the earth as it revolves around the sun which is due to gravitation as described by general relativity, etc. If any step in the causal chain from gravitation to summer warmth is eliminated, the effect is eliminated. If the earth ceased to tilt or revolve, or the sun cease to shine, or gravity cease to operate, summer would cease.
But these ordered causal chains in the universe can’t regress to infinity because there must be a fully actual cause at the beginning that gets the chain going. That fully actual cause cannot itself depend on any other cause within the system. Otherwise, how would it start?
Imagine a chain hanging from the sky supporting a weight suspended in the air. Each link in the chain is a cause for the continued suspension of the links and the weight they hold up. However, the chain could not hold itself up alone. It can’t be “links all the way up.” Something at the beginning must be holding the chain up. And whatever holds the whole causal series up cannot just be another link in the chain. To be a “first cause,” whatever is holding up the chain must be something different from the chain itself.
In the same way, the cause of the universe must be something other than the universe itself and must have the power to cause things independently of the laws of nature. That is what all men call God.
A second reason why the universe cannot be the most fundamental thing is the principle of sufficient reason. In its most distilled form, the principle states that every fact in the universe has a reason sufficient to account for it. We may not know the reason for every fact and we may not even be able to know the reason for every fact. But we must infer that there is a reason for every fact.
For example, imagine waking up one morning and finding a car parked in the front yard. That would be a strange thing — and we might infer that somebody got drunk and inadvertently parked in the yard or perhaps the car was left there after a collision. Or possibly it was someone’s idea of a practical joke. But we cannot infer that the car is there for no reason whatsoever. We intuitively understand that there must be an explanation, even if it is hard to come by.
Now let’s assume that the universe itself exists for no reason. Then everything that exists violates the principle of sufficient reason. If the whole universe doesn’t need a reason, then nothing within the universe needs a reason. Then science would be impossible, because anytime a scientist tried to explain the existence of a subatomic particle, a star, or a species, one could simply say that they existed for no reason at all and that would count as a scientific explanation.
Denial of the principle of sufficient reason would make ordinary life impossible — we would have to accept that everyday occurrences in our lives could well have happened with no explanation whatever. But in reality, even chance occurrences happen in accord with physical laws and thus happen for reasons.
Atheists who deny that God exists deny the principle of sufficient reason for the universe. In doing so, they must also deny our common-sense experience of the world and they must even deny science itself. So the answer to the objection “But then God Himself needs sufficient reason to exist” is straightforward: God is supernatural and self-subsistent and thus is the First Reason. He is not in need of a reason for Himself.
As I said before, the existence of God is a more well-established scientific fact than any other theory in science. In fact without God as Prime Mover and sufficient reason, science itself would be impossible. It is deeply ironic that atheist scientists, by denying God’s existence, deny the rational basis for their own profession.
You may also wish to read: Here’s why an argument for God’s existence is scientific: The form of reasoning and the type of evidence accepted is the same as with Newton’s theories or Darwin’s. We can observe God’s effects in the natural world just as we inferred the existence of the Big Bang and black holes by observing their effects. (Michael Egnor)