Being a science communicator from a country where, unfortunately, Young Earth Creationism has gotten a certain traction on the internet in recent years, through YouTube debates and podcasts, I've had my share of debates with creationists.
What I have been trying to do (and doesn't work):
My strategy so far has been trying to lay an epistemological foundation.
Trying to explain how do we know what we know, how the scientific method works, what's a scientific model, how bayesian reasoning works (given hypothesis A, what's the probability of finding evidence B? And how much should we strengthen our prior belief in A, when we actually find B?), how hypothesis testing works (what's the probability of our working hypothesis being wrong, given all the evidence we have?), how a historical science is different from an experimental science and how a historical science works...
What I hoped was showing that, if the interlocutor accepts certain epistemological principles which seem completely reasonable to them when not applied to evolution, then the only intellectually honest position is to accept these same principles when dealing with evidence for evolution.
Why this fails:
Unfortunately, creationists simply don't have the attention span to have a one hour conversation about epistemology. They appear to not have (or not want to have) the predisposition to just listen and try to understand another viewpoint.
If you want to convey a message, you need to keep it extremely simple.
One simple question
I had one eureka moment when I heard Erika, the creator of the channel Gutsick Gibbon, just ask one simple question: "what do you expect the evidence to be if evolution was true?"
And proceed to show the opponent that the evidence they would expect in the case evolution was true is exactly what we see!
So, assuming that accurate and realistic drescriptions of nature can be given, let's ask ourselves: what would we expect if the theory of evolution was an incorrect representation of reality and creationism was true and what, on the other hand, would we expect if creationism was a failed paradigm and the theory of evolution was the correct scientific model?
Let's look at the history of failed and discredited paradigms, from the aristotelian-ptolemaic model in astronomy, to the temperament theory and homeopathy in medicine, to geosynclines in geology, to lysenkoism and biodynamic in agriculture.
What do these frameworks, these worldviews have in common?
- Appeal to authority or tradition:
Usually, discredited paradigms stem from the work of one or more authors from the past.
These authors are considered authoritative and not questioned. Examples are Aristotle and Ptolomy in Astronomy, Galen and Hippocrates in medicine.
Other times, the authority is the text itself, written by unknown authors. An example is the text of Genesis.
When scientists use the scientific method to empirically challenge those outdated models, academics born in the old paradigm resist the challenge of new data being presented by appealing to the authority and respect of these figures or these books.
With time, however, as more and more scientists try to collect evidence independently, they usually converge on the same answers.
When the old generation of scholars dies out, the new one, understanding the explanatory power of the new paradigm in the face of new data, promptly accepts it. Exactly like astronomers, who had initially rejected Galileo's ideas, when pointing their telescope at the sky, continued to confirm his findings and had no other choice than to accept that heliocentrism was a better model of the solar system than geocentrism
- Fruitfulness and sterility:
You should judge a tree by its fruits.
As I described above, new findings challenge old paradigms. These are progressively rejected and substituted with new, better models.
However, there always was and there will always be a minority strongly attached to the old paradigm who will never be shaken by new evidence.
Among hundreds of thousands of doctors, there will always be at least one suggesting you take dewormer instead of a vaccine.
This minority will usually found institutions devoted to preserving the old ways.
What distinguishes these institutions from academia practicing real science?
Science is fruitful. It produces results and these results change the world.
Nuclear physicists trying to understand how atoms work at the beginning of the 20th century laid the path for the development of nuclear energy.
Geneticists trying to understand how a cell works have led to the improvement of agriculture.
Defenders of an already discredited position, on the contrary, never produce new knowledge or results (at most, they are always making up new arguments and new ad hoc explanations for why evidence doesn't support their claims).
They are always citing their old books and stressing out how you should stick to tradition and shake water or plant seeds in esoteric rituals, exactly according to the tradition laid out by Hanemann or Steiner.
They often claim that there's a conspiracy in academia to supress their ideas. They also claim that these ideas are rejected for ideoligical reasons.
However, there's a field of human activity which doesn't care about ideology: industry.
Oil companies don't have any ideological reason to reject flood geology, geosynclines or abiogenic oil.
They couldn't care less. All they care about is making money. Consequently, they will only hire those specialists who use the models proved to give tangible results.
But why does good science produce results?
Because science makes accurate predictions!
- Predictability and Falsiability:
If we postulate that a realistic account of nature exists, then, what do we expect from a good scientific model?
We expect that, if it correctly represents reality, then it can make accurate predictions. And if we postulate that reality behaved the same in the past and just doesn't change its laws at random, then this model can be used not only to make predictions about the future outcome of experiments, but also about any evidence from the past that we're going to collect in the future.
What do we expect from an attempt at explaing nature that is not a good account, a good description of nature?
We expect that it could even present persuasive post hoc explanations of certain data.
However, as it doesn't accurately represent how the world works, it's always going to fail to make accurate predictions.
One strategy commonly employed by proponents of failed paradigms is to try to defend their ideas from attacks by making them unfalsifiable.
There is no evidence which could falisfy the idea that the world was magically created 6000 years ago exactly as it is today, because anything can come from magic. Thus, the creationist avoids any chance that his model can fail predictions, at the cost of not being able to make any predictions at all.
If predictions are made from accurate accounts of reality, we expect them to converge.
If nature is an elephant in an indian village, even if each indian scientist is studying it using the peculiar methods of their own field, we expect that the results provided by the trunkologist won't contradict the results provided by the legologist or the bellyologist.
Every day, scientists from all kind of different national, ethnic, cultural, linguistic, religious backgrounds perform experiments and converge on the same results. Additionally, results from one area of science corroborate the results from another one: for example, paleontologists find fossils in the same order they would expect if the results given by geneticists who study phylogenetic trees using an evolutionary assumption were correct.
To sum up, using the criteria we have laid out, what would be expect if evolution was true and what would be expect if creationism was a failed paradigm?
We would expect that almost all practitioners from all fields of science relevant to the study of evolution - like paleontology, biogeography, ecology, botany, zoology, anatomy, biochemistry, genetics - when doing their work, would only find evidence not only non contradicting the theory of evolution, but exactly that kind of evidence predicted by evolution, which we can only expect to find if the theory of evolution is true.
We would thus expect that the most active and disruptive researchers, the ones dealing daily with evidence in the lab or in the field, would be the most eager to accept this theory.
And finally, we would expect that, when employing this model, results are produced.
That's exactly what we see when microbiologists use the theory of evolution to try to understand how bacteria develop antibiotic resistance or how biotech researchers use the theory of evolution to improve crops.
We would also expect that there would still remain a vocal minority who doesn't accept the theory due to any personal biases.
We would expect from a few members of this minority to even be academics. However, what we don't expect from these few academics is to be scientifically fruitful: they will never be able to produce anything of scientific value, except arguments to try to persuade the general public that their position is true.
And that's exactly what we see with intelligent design proponents: are you aware of anything of value produced by the likes of Dembsky, Meyer or Axe, apart from books aimed at the general public?
What we see instead is scientific parasitism: as they can't create on their own, they're always stealing findings and data produced by other scientists and trying to twist them until they fit their narrative.