Philosopher of biology Paul Nelson constructs an imaginary but not uncommon exchange between a Darwinian (Evolver) and an Intelligent Design advocate (Designer):
Designer: The formation of proteins from amino acids cannot occur in an aqueous prebiotic setting. Hydrolysis will attack the peptide bonds —
Evolver: Excuse me for interrupting, but that is not how proteins formed.
Designer: In the Oparin-Haldane model —
Evolver: You mean the Oparin-Haldane strawman?
Designer: But their “thin organic broth in a reducing atmosphere” was the leading prebiotic scenario for much of the 20th century.
Evolver: Hello, it’s 2020. The field has moved on. Proteins exist, so using a prebiotic soup model for their origin, when we already know that doesn’t work, cannot be right. You need to address the actual prebiotic pathway that occurred, not some old and erroneous hypothesis.
Designer: All right, what is the actual prebiotic pathway to proteins?
Evolver: We’re working on that. The tour bus is leaving, try to keep up.
Nelson states that "We could continue this dialogue indefinitely, with Designer critiquing as unworkable, or false, every prebiotic protein origins hypothesis put forward by Evolver — and yet Evolver stands there, untroubled, yawning and checking the messages on his iPhone."
The reason that no progress can be made in such an encounter is because of an unstated assumption in Evolver's argument. Evolver tacitly assumes that naturalism, the belief that there are no non-natural forces at work in the universe, i.e. that there's no supernatural agency, is true. Here's the argument as it might appear to an onlooker (I've altered Nelson's version a bit):
1. Proteins exist.
2. Naturalism is true (tacit assumption)
3. Therefore, any non-naturalistic explanation for the existence of proteins must be false.
Obviously, this argument hinges on the truth of premise 2, but that premise is not a scientific assertion, it's metaphysical. It's a philosophical assumption for which there's scant, if any, evidence.
Designer's argument might go something like this:
1. The genesis of proteins is exceedingly improbable on any naturalistic hypothesis.
2. Proteins exist
3. Therefore, it's exceedingly improbable that naturalism is true.
The debate then is not really over the science. Evolver's commitment to a naturalistic explanation for all biological phenomena is not scientific, it's psychological. It's not based on any empirical evidence but rather on a psycho-emotional preference. It's the same sort of commitment that many people make to their religious beliefs.
Thus, Designer's task is a difficult one. His argument is scientific. It's based on biochemistry, probability and information theory, all of which militate against Evolver's naturalism. Nevertheless, no matter how much evidence he adduces to show that the biochemical hurdles to a naturalistic origin of the first proteins are astronomically high, Evolver will simply take refuge in his faith that naturalism is true and that there must therefore be some naturalistic explanation for how proteins evolved.
The irony is that Designer's case is scientific but points to a supernatural agent as the architect of the first life whereas Evolver's argument dresses itself up as science in appealing to natural forces as the cause of living things, but it has, in fact, much more in common with religion than does Designer's argument.
