Odd arrangements and funny solutions are the proof of evolution—paths that a sensible God would never tread but that a natural process, constrained by history, follows perforce. No one understood this better than Darwin. Ernst Mayr has shown how Darwin, in defending evolution, consistently turned to organic parts and geographic distributions that make the least sense.
Other times the theism is slightly more subtle, such as when Charles Darwin explained that:
We cannot believe, that the similar bones in the arm of the monkey, in the fore-leg of the horse, in the wing of the bat, and in the flipper of the seal, are of special use to these animals. We may safely attribute these structures to inheritance.
You can read more about this subtle example of religious reasoning here. The problem is not that these proofs are invalid. In fact, the evolutionist’s logic is perfectly valid. But the arguments begin with metaphysical premises about a creator. In other words, the conclusion that evolution is a fact hinges on non scientific premises from theism. If those premises are true, then evolution is a fact. If the premises are not true, then we have no such confidence. It all depends on the religious starting point.
Now in our society, which holds science in such high esteem, evolution’s religious reasoning may seem like a terrible idea. But actually it is not. There is nothing wrong with non scientific, theistic, reasoning. In fact we use such reasoning commonly in our daily routines. Nor is such reasoning necessarily a problem within science. It happens more often than many think.
What is a problem is denying the religious reasoning. There is nothing wrong with making theistic premises, but there is everything wrong with masking the argument with some other label, to avoid the underlying religion. Not only is evolution motivated and justified by their religious beliefs, but those beliefs are routinely denied. You can read more about this denial here.
But evolutionists are not the only ones who deny this religious foundation. Such denial is also common amongst those who argue against evolution. Creationists, IDers and others commonly ascribe evolutionary thought to atheism rather than theism. In the face of a continual drumbeat of religious claims, these opponents say evolution arises from a rejection of theism. Consider these facts:
1. Evolution opponents have been labeling evolution as atheism for centuries, long before the recent surge of atheism.
2. This atheism label is applied to arguments that make theistic truth claims—claims that could not possibly derive from atheism. (Atheism states there is no god and only matter and energy exist. Therefore atheism cannot provide truth claims about a non material world).
3. This atheism label is applied to openly confessing theists, usually Christians.
4. It is true that atheists also assert evolution’s theistic truth claims, but this simply reveals an inconsistency with their claim to be an atheist. Theistic truth claims can only come from theism, no matter who is making the claim.
Consider the case of Thomas Burnet. Burnet was a seventeenth century Anglican cleric who made several religious arguments for a mostly naturalistic creation narrative. Burnet was an influential thinker and many of his arguments became important in evolutionary thought. But in 1692 Richard Bentley accused Burnet of atheism.
In the eighteenth century James Hutton, a devout Christian who advocated uniformitarianism, was accused of atheism by geologists of the day. In the nineteenth century one of the first serious criticisms of Darwin’s theory of evolution by Charles Hodge charged that the theory was atheism in disguise in spite of Darwin’s endless trail of religious claims. More recently Alvin Plantinga has also suggested atheism as the source the evolutionist’s confidence.
Plantinga has made a great many cogent observations and criticisms of evolution. And he correctly identified the claim that evolution is a fact, as non scientific. But in spite of the never-ending theistic claims, Plantinga suggests that the source of evolutionary certainty is a rejection of theism:
If you reject theism in favor of naturalism, this evolutionary story is the only game in town, the only visible answer to the question: Where did all this enormous variety of flora and fauna come from? How did it all get here? Even if the fossil record is at best spotty and at worst disconfirming, this story is the only answer on offer (from a naturalistic perspective) to these questions.
For more than three centuries evolutionary thinkers have been making theistic claims which mandate a naturalistic creation narrative. And for just as long, opponents have been denying those theistic claims.