What fallacy of argument is this?

More than once, and again recently, I heard a skeptic arguing against the validity of the supernatural on the grounds that you can’t use science to prove it (reason, philosophy, deduction, etc… need not apply, I suppose). For example, he said if cancer goes into remission, there’s no scientific way to determine the Virgin Mary’s involvement. On the issue of “ghost” activity, he used the same argument that our inability to “explain” something scientifically does not allow us to draw supernatural conclusions.

One of the problems with such logic, as I see it, is that the skeptic’s assertions themselves are unprovable by science. For instance, what scientific experiment can you conduct to make the claim “in order for something to be true, it has to be demonstrated by science”? The claim itself is unscientific. Thus, it is self-defeating.

What’s the fallacy for such line of thinking?

Is that what is called “begs the question”? Understand that I know VERY LITTLE about logical fallacy. But if he says his position is correct because the opposing position can’t be proved by science, then it “begs the question” of is his position proved by science, and if not, why is is valid?

Buta again, this “logocal fallacy” stuff tends to confuse me. :blush:

I don’t think it’s begging the question.. It sounds more like accident.

The argument is, more or less:
Something is true only if it can be proven by science.
Christianity/Theism/etc cannot be proven by science.
Therefore, Christianity/Theism/etc are not true.

I don’t see so much a formal fallacy as a bad, overly broad premise - something is true only if it can be proven by science. There is indeed a broad class of things that can only be proven scientifically, but there’s another class of non-deductive truths, including the premise itself.

This is a very bad argument, as you have stated. Basically, this arguments actually says that science can prove that the supernatural doesn’t exist. Follow my lead here:

If Science can’t prove that the supernatural exists and we take as a fact that this proves that the supernatural doesn’t exist then science proved that the supernatural doesn’t exist.

As my two year old would say, “That is silly, Daddy!” Silly indeed.

The real problem is the misuse of science by the arguer. The truth is that the practice of science is drawing conclusions based on facts gathered through observation. If there is no distinct pattern to the facts observed than no conclusion can be drawn at all. So the scientific response to cancer being extraordinarily cured is that there is no response. Science can draw no conclusion on such matters. End of story. Any ‘conclusions’ made at this point are only editorial conjecture or opinions, not scientific conclusions.

And one more point, the very meaning of ‘supernatural’ is ‘beyond nature’ or ‘greater than nature’. Since science (at least the type of science I assume the arguer would refer to, i.e. biology, physics, chemistry, etc.) works in the natural realm by definition it cannot have anything to say about the supernatural.

The general problem is thinking that everything important is necessarily provable.

Many important things are not provable: Love and faith for example.

One way of looking at this is that his argument fails because it is not immaterial. What I mean is that he accepts only the material realm, which can be physically demonstrated. Yet, his imagination, which is immaterial, formed his question! Can science explain why he has doubt? Is there a measurable physical or chemical difference between a mind that doubts and one that believes? He fails to admit to the immaterial - such as his very soul. A dead creature contains the exact physical elements as a living one. The difference is in the immaterial - the presence or absence of a spirit.

First, I’ve put up a reference that I no longer maintain about rhetorical arguments in apologetics:


There’s a couple of ways of looking at the fallacy below -but the important point is that it’s a fallacy, it’s not a logical argument.

On the first note, this is an unchallenged assumption of paradigm - that the decision rule is simply asserted as “it must be provable under experimental conditions”. While that’s not a logical fallacy per se, it’s an assumption, and all arguments comprise two parts:

  1. Assumption
  2. Logic

If you remove the assumption, the logic is irrelevant, and vice versa. So attack the assumption, ie:
a) “Experimentation is not a valid paradigm here - you can’t prove your wife’s love for you in such a way”
b) Assert the contrapositive - say “Okay, we can use the empirical rule but it must apply to all methods. Here’s the case of a miraculous healing that has no known scientific cause. If you can find a scientific cause, I’ll accept that it wasn’t a miracle. But without a known scientific cause, the miracle remains just as valid as an unknown scientific cause.”

Now in this light it is a logical fallacy, that of asserting a decision rule designed to undercut existing evidence. A common example is used by Muslim proselytizers:

“Unless you can show me where Jesus says ‘bow down and worship me’, I won’t believe that Jesus is God.”

Well nowhere in Scripture does Jesus say this. It may sound convincing, but it’s not logical. Consider that Scripture never says “Premarital sex is a sin” but that’s a nonsense argument.

I’d also argue what “science” means. Until recently, scientific proof of the Higgs Boson did not have the same approach as scientific proof that sunlight makes plants grow. The former is mathematical and deductive, the latter experimental. Put it this way - we could prove that uranium is harmful to human life by having 100 people drink a

Unless he maintains that (all) propositions must be scientifically verifiable, his position is not self-defeating.

Simply stating that, in the event of a seemingly miraculous event, science cannot invoke the non-empirical in its explanations of the said event, is not fallacious. For what it’s worth, there are prominent Christian apologists that agree with this assertion.

Consider for example, reported near death experiences (or post-death experiences, a more accurate label).

There is a way to verify that a person was conscious after clinical death, (for example, if the patient can, upon recovering from death, report an incident that is not physically or tangibly possible for him to have knowledge of, e.g. details of an accident that occurred across the street from his hospital and during the time in which he was dead).

We can verify his post-death consciousness because we can verify whether the details of the accident are true/whether the accident occurred, and can, at least in theory, eliminate proposed physical and practical avenues through which the patient could have learned of the accident (e.g. hearing nurses in his room talk about it upon him recovering some brain activity).

However, if the person claims to have seen heaven and Christ during his dead-but-conscious phase, we cannot verify that claim – that content of his post-death expierience would not be scientifically verifiable. All that science could conclude is that he was conscious post-death.

I recommend listening Christian apologist Gary Habermas on the subject of NEDs – which ties into your OP.


Fallacy: The supernatural/preternatural are interactions with persons. The insistence on “science” to prove it is fundamentally flawed.

If I were to ask you, “Where’s the bathroom?” repeatedly - your answers would be different most every time.

1st time: “Down the hall, to the left.”
2nd time: “Ummm - well - you see that hall? Just go down that hall - it’s on the left.”
3rd time: “I just told you - why do you keep asking?”
4th time: “Oh, I get it - you’re just being annoying. Buzz off.”
5th time: “OK - I’ve got stuff to do, so I’m done with this game.”
6th time: “I’m calling the cops.”

The material world is different. Each time the object in motion impacts the second object, some of the energy is transmitted into the second object while the first object changes velocity. The same way - every time - endlessly. It doesn’t change.

I think we’re talking about 2 different things here. I was not referring to his claim on the Virgin Mary at that point.

The skeptic’s claim that I said was self-defeating is that “in order for something to be true, it has to be demonstrated by science.” That claim itself cannot be demonstrated scientifically.

Interesting responses everyone. :o

Indeed - many times have I found myself asking “On what basis must we accept your assumption?” (although I usually say “criteria”)

In my anecdotal experience, I have seen this more than once in skeptics’ apologetics. A common one is: “if God exists then he would do XYZ!” And you think to yourself - Why should we impose that specific criteria? You can get into some crazy discussions…

I was thinking more like

Something is true only if it can be proven by science.
The claim above cannot be proven by science.
Therefore the claim above is not true.

What do you mean by ‘the claim above’? Do you mean the claim that Christianity can’t be proven by science? If so, that’s just kind of a restatement of my syllogism. Or do you mean ‘the claim above’ as referring to premise 1? My symbolic logic is a bit rusty, but I think that’s actually a valid argument.

I guess I’m not really sure what you’re trying to say. (Also, I’m so glad I found an excuse to break out my symbolic logic textbook. Favorite college class.)

I meant premise 1.

snarflemike is correctly saying what I was trying to say. To paraphrase once more:

CLAIM X says something is true only if it can be proven by science.
CLAIM X itself cannot be proven by science.
Therefore CLAIM X says itself is not true.

This is what I called “self-defeating” in the OP. Is there a term for this fallacy that hasn’t already been articulated?

Well said. I’ve also heard it said that one can’t put God in a test tube.


Hi Marco. Keep in mind that an argument does not have to be fallacious to be disproven. Logical arguments (like chains) are only as good as their weakest link. In this case, the weak link is the 1st premise: Something is true only if proven by science. All you have to do to break this link and destroy the argument is to give one example of something that is true, which is not proven by science.

History comes to mind. No one can put the Julius Caesar in a test tube to prove he was the first emperor of ancient Rome. This is proven by historical documentation, not science. (Now if the skeptic says archaeology proves this, simply ask if a lack of any surviving archaeology would prove Julius never existed, or use a different example, such as Aristotle. We know he existed as a result of his writings, and the writings of others, rather than as a result of science.)

Once she agrees something that is not proven scientifically can indeed be proven historically, simply point out that her premise does not support her conclusion. For you and she will then both agree that not all truth is proven to be true by science alone. You may then go on to discuss the historical, written evidence for the life, death and resurrection of Jesus Christ, which gives sound evidence for the existence of God. You might even want to say there is far, far more such evidence supporting Jesus than there is supporting Julius.


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