Reading Time: 9 minutes Potential abiogenesis at Tynagh Chimneys By Richard Robinson (PLoS) [CC BY 3.0 (], via Wikimedia Commons
Reading Time: 9 minutes

Logic of Science, which looks like a really interesting blog over here, gave me permission to repost this good synopsis of theists’ approach to abiogenesis in the context of the sort of Goddidit Argument from Ignorance we so often see, and have seen here from some commenters.

Here is the summary, and thanks again:

“Where did life come from?” It is a question people have thought about for millennia, and it is a question that is worth trying to answer. Nevertheless, not everyone is interested in looking for that answer. Indeed, many people prefer to simply insert god as the answer rather than actually wrestling with the question. Even worse, young earth creationists, intelligent designers, and some theistic evolutionists cite the current lack of a scientific answer as evidence that there is no scientific answer. In other words, they use the gap in our knowledge as an argument for a creator, and insist that since science doesn’t currently have an answer, the answer must be god. In reality, however, this argument violates fundamental concepts of both logic and science. Therefore, I want to talk about it and explain why it is not valid to say, “science can’t explain this, therefore god did it.”

Note: As always, this post is about science, not whether or not god exists. If you are a Christian or any other form of theist, I do not want you to read this as an attack on your religion. All that I am doing is addressing one particular, flawed argument. For the sake of this blog, I don’t really care what you believe as long as it does not cause you to reject science. That isn’t to say that debates about whether or not god exists aren’t worth having, but simply that this blog isn’t the place for them.

Abiogenesis is not the same as evolution

Before I can talk about the argument itself, we need to get our terms straight. Abiogenesis refers to the formation of a living cell from non-living matter. Evolution refers to the changes that occurred to life after the first cell formed (technically speaking, evolution is simply a change in the allele frequencies of a population over time). So, abiogenesis and evolution are not the same thing, and you cannot use them interchangeably, nor can you use an argument about one as evidence against the other. To put that another way, the theory of abiogenesis deals with how life formed, and the theory of evolution deals with what happened after life formed. They are not related to each other, nor do they depend on each other. Therefore, even if you could somehow prove that it was impossible for a cell to form from non-living matter (which you can’t, btw), you would have done nothing to discredit evolution. In other words, you would have shown that a creator had to make the first cell, but you would not have shown that evolution did not take place following that initial creation (indeed, that is precisely what some groups of theistic evolutionists believe).

Argument from ignorance fallacies

Now that we have our terms straight, let’s turn to the argument itself. It is true that scientists currently do not know exactly how the first cell formed. We have made a lot of progress in understanding it, but we have yet to get all the pieces together and actually make a living cell. Keep in mind, however, that the chemistry of life is exceeding complex, so it is hardly surprising that we have yet to complete such a complicated puzzle. Nevertheless, the current lack of a scientific explanation leads to the exceedingly common argument that since science does not currently have an answer, the answer must be god. That argument is, however, fraught with problems, the most obvious of which is the blatant argument from ignorance fallacy. I realize that tossing around the names of logical fallacies tends not to convince people, so let’s talk about this. I want to explain what that means, and why it is a problem.

An argument from ignorance is basically just an argument that fallaciously uses a lack of evidence as evidence of something else. In other words, it takes a gap in our knowledge, then inserts an assumption into that gap and attempts to use the gap as evidence that the assumption is true. Let me give you a few examples.

“No one has proved that Bigfoot doesn’t exist. Therefore, it exists.”

This argument is an argument from ignorance fallacy because it because it takes the gap in our knowledge, and inserts an assumption as if it is a fact. Do you see how that works? The fact that we have not proved with 100% certainty that Bigfoot doesn’t exist does not in any way shape or form constitute evidence that it does exist. Indeed, this example (and many others like it) attempts to shift the burden of proof. The person making the claim is always responsible for providing evidence to back up their claim. Thus, if you want to claim that Bigfoot exists, you have to provide actual evidence for its existence. You can’t simply appeal to the fact that it has not been 100% disproven. To use a related example, if someone believes in unicorns and you ask them for evidence that unicorns exist, they clearly can’t respond by simply saying, “prove to me that they don’t exist.” A claim has to have actual evidence to support it, not just a lack of evidence against it.

Now, let’s look at an example that is a bit closer to the topic of abiogenesis.

“Scientists can’t explain dark matter. Therefore, it is being created artificially by aliens.”

Hopefully you can see why that is a problem. I obviously cannot take our current lack of understanding and just insert aliens. Rather, I would need to provide actual evidence that the aliens existed, and I would need to demonstrate that science truly can’t explain it rather than simply showing that science hasn’t explained it yet (more on that in a minute).

Now, let’s get back to abiogenesis and compare it to the examples. You should notice that it is logically identical to my absurd alien argument. Indeed, we can state it simply as,

“Scientists can’t explain abiogenesis. Therefore, life was created by god.”

The same problems that existed for the alien argument exist for this argument. You can’t insert god into our lack of understanding about abiogenesis any more than I could insert aliens into our lack of understanding about dark matter. You must provide actual evidence that god exists before you can use him as an explanation, just as I would be required to provide actual evidence that the aliens existed before I could use them as an explanation.

Indeed, this particular argument is what is known as a “God of the gaps” argument. These are just special cases of argument from ignorance fallacies where you insert god (or a supernatural force more generally) as the explanation for an unknown. In the days before science, these arguments were abundant, and almost everything had some supernatural explanation. As science gradually provided explanations for our natural world, however, these arguments slowly fell out of favor, and today, even most creationists eschew them. Or, at least, they claim to eschew them, because this abiogenesis argument is clearly nothing more than a God of the gaps argument. It takes a gap in our knowledge and it inserts god as the explanation, which makes it, by definition, a God of the gaps argument, whether creationists like it or not. This brings me to my next major point.

“No explanation” and “no current explanation” are not the same thing.

If you are struggling to understand why creationist’s argument is problematic, think about this way: for everything that science can currently explain, there was a point in time at which the explanation was unknown. Imagine, for example, someone before the discovery of DNA saying, “science can’t explain genetic inheritance, therefore god is causing it” or, before we understood tides saying, “science can’t explain the tides, therefore god is causing them.” In hindsight, those arguments are obviously flawed, and it is clear that science simply hadn’t explained them yet rather than science being incapable of explaining them. Abiogenesis is no different. The fact that we haven’t explained it yet doesn’t mean that there isn’t a scientific explanation. It just means we haven’t found it yet. Indeed, we do science precisely because there are still unknowns. If we had scientific explanations for everything, then there would be no reason to even bother doing science. Thus, you can’t make a statement like, “science can’t explain abiogenesis.” Rather, all that you can say is, “science hasn’t explained it yet.

To put all of this another way, imagine that, in the past, every time that scientists encountered something that they couldn’t explain, they simply gave up and said, “well, we can’t explain it, so I guess god must have done it.” That would obviously have been terrible, because science would never have progressed. Nevertheless, that is exactly what creationists are doing. Rather than actually looking for a scientific explanation for something that is currently unknown, they are content to attribute it to the divine.

I really like the Socratic method, so let me phrase this as a question. If you agree that it would have been logically invalid for past generations to insert the supernatural as an explanation for things that they did not understand, then why do you think it is ok to insert god as an explanation for what we don’t understand (e.g., abiogenesis)? That strategy would clearly have failed in the past, so why do you think that it is ok now?

No, scientists aren’t making an argument from ignorance

Finally, I want to address a rather creative, albeit misguided, tactic that I sometimes see people use at this point in the conversation. Upon realizing that their position commits a fallacy, they try to flip things and assert that scientists are also committing an argument from ignorance fallacy, because scientists are “assuming” that a natural explanation exists. In other words, they claim that scientists are saying, “creationists haven’t proved that god did it, therefore it is natural.” At a quick glance that might seem like a correct assertion, but if you examine it more closely, you’ll quickly realize that it is actually ignoring basic concepts about how science works.

First, science always “assumes” that a natural explanation exists. That “assumption” is fundamental to science and indeed necessary for it, because science is, by definition, the study of the physical universe. If we didn’t “assume” that natural explanations exist, then there would be nothing for us to study. We’d be back to shrugging and saying, “god did it.”

Let me give you an example. My PhD research is focused on understanding why some populations/species recover from disease outbreaks while other, seemingly similar populations/species don’t. Several previous researchers have worked on my study system, but so far, no completely clear answer has emerged. Much like abiogenesis, we have some of the pieces of the puzzle, but we haven’t put it all together yet. Now, obviously, I am operating on the “assumption” that a natural explanation exists. Am I committing an argument from ignorance fallacy? Of course not! It would clearly be crazy for someone to say, “scientists can’t explain why these populations recovered. Therefore, god performed a miracle.” I doubt that even the most ardent creationists would consider that to be a rational argument. Thus, the rational position is clearly to operate as if a natural explanation exists, and, indeed, that is how all science operates. So why should abiogenesis be any different? Creationists are holding abiogenesis to a different standard than all of the rest of science.

This brings me to my next major point. “Assuming” that a natural explanation exists should be the default, because natural explanations are all that we have ever found. Think back to my initial examples of argument from ignorance fallacies. They all assumed the existence of something that there was no actual evidence for (Bigfoot, god, aliens, etc.). In the case of science, however, natural explanations have always been the answer to every mystery that we have ever solved. That’s why I keep putting the word “assumption” in quotes. Thinking that a natural explanation exists is not an “assumption” in the normal sense of the word, because it is blatantly obvious that a physical universe exists and follows natural laws.

To put that another way, you have to provide evidence that something other the natural universe even exists before you can criticize the “assumption” of a natural explanation. It would obviously be absurd, for example, to criticize a scientist for “assuming” that that the answer wasn’t magical unicorns. You would need to provide evidence that magical unicorns exist before you could even propose them as a valid explanation. Even so, you can’t even propose god as an explanation for a scientific unknown unless you have first provided evidence that such a being exists.


In short, using our current lack of understanding about how life formed as evidence of a creator ignores the rules of both logic and science. It is nothing more than an argument from ignorance fallacy (specifically a god of the gaps argument), and, as such, is not logically valid. The fact that science hasn’t found the answer yet simply means that science hasn’t found the answer yet. Nothing more. You can’t insert god as an explanation any more than you can insert aliens, unicorns, multi-dimensional beings, the tooth fairy, etc. You have to provide actual evidence for those things rather than simply saying, “we don’t know, therefore god.” For every mystery that science has ever solved, there was a point in time when the answer was unknown. Further, when those mysteries were solved, the answer was always a natural explanation. Therefore, a current lack of a scientific answer is clearly not evidence of the divine, and there is no reason to treat abiogenesis any differently than any of the thousands of other mysteries that scientists are currently trying to solve. For essentially all of those unanswered questions [except abiogenesis], even the most adamant creationist would agree that we are correct to assume that the answer will be a natural one. So why should abiogenesis by any different?

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Jonathan MS Pearce

A TIPPLING PHILOSOPHER Jonathan MS Pearce is a philosopher, author, columnist, and public speaker with an interest in writing about almost anything, from skepticism to science, politics, and morality,...