What is self-refutation and what are some examples of self-refutation?

Why, self-refutation is the most wonderful thing in the world, next to irony.

Look at this post from Thinking Matters New Zealand.

First, they define what self-refutation is:

In his Introduction to Logic, Harry Gensler defines a self-refuting statement as “[A] statement that makes negative claims so sweeping that it ends up denying itself.” [1] In other words, it results when an argument or position is undercut by its own criteria  (An example of this would be saying, “I cannot speak a word of English” in English).

Then they have a list of examples of self-refutation. Here are some:

  1. Truth does not exist (Is that a true statement?)
  2. Nothing is absolute (Is that absolutely true?)
  3. I do not exist (You must exist to deny that you exist)
  4. Science is the only way to know (Can you scientifically prove that?)
  5. Only what can be perceived by the five senses exists (Can you prove that by the five senses?)

Go here to read the rest.

I work in the software engineering industry, so we have a lot of nerds running around who believe all kinds of crazy things that are self-refuting. There is a lot of skepticism of the laws of logic and analytical philosophy. A self-refuting statement that I hear a lot is: “Don’t judge me, because it’s wrong to judge other people”. And I just ask them: “Well if it’s wrong to judge other people, then why are you judging me?”. (Actually, I noticed that MandM has a post up about judging right now!)

I wonder if my regular readers have ever heard any self-refuting statements? If you know any more, leave it in the comments.

On another topic, it turns out that the author of this post on self-refutation blogs at Rational Thoughts. I added their blog to the blog roll. Check them out.

20 thoughts on “What is self-refutation and what are some examples of self-refutation?”

  1. I hear “All religions are equally true” sometimes. But all religions inherently exclude one another. And in my experience it is extremely difficult to reason with people who believe such statements. Reason, logic, and truth are not their real goals, and they’re willing to contradict themselves if they have to.

    1. I’ve also noticed this. The thing that I do is to ask them whether it is potentially dangerous to create a worldview based on the need to be happy and to be liked by other people. I ask them them if they would choose a medication based on peer-pressure and the need for self-esteem. If they say no, then I ask why they form a worldview of religious pluralism based on those concerns.

      1. Thank you for this. I’m engaging someone right now who has that *exact* thought process. I’ve been mulling it over and trying to figure out where the most effective place to start is.

    2. In fairness, the statement “all religions are equally true” is logical if all religions are completely false (i.e. they share a truth value of 0). Although I doubt that’s what the people you’re talking about had in mind.

  2. I don’t really see the problem here, actually. Tarski and meta-statements and stuff can surely avoid these difficulties. Usually cosmetic changes these bald ‘self-refuting’ statements can cure their self-refutation.

  3. “Nothing is absolute (Is that absolutely true?) ”

    The reply I had to that from an Atheist was to say no that it is systematically true.

  4. Hey Wintery Knight! Your blog is a like a breath of fresh air in the midst of stiflingly bad thinking!

    I’m currently in the middle of a conversation with two atheists who have made the following comments:

    > “All truth is subjective.”
    > “On a scale of 1-100 I would give agnosticism a 50.”
    > “I don’t know if objective truth exists.”
    > “I’m not sure of anything.”
    > “I preface every statement about any subject (God, gravity, truth, etc.) with: ‘Based on my knowledge, understanding, and interpretation of the prevailing evidence, I tentatively believe that…'” (That’s an interesting one!)
    > “Either-or questions are illogical.”

    Here’s the conversation thread, in case you want to contribute! :-)
    http://www.bobmo.com/2009/12/question-for-agnostics.html

  5. Now, I’m told that “Binary logic is not relevant in a system of quantum logic. Things can exist, not exist, or be in a state of exist/not existence.”

    I wonder if that’s either true or false? ;-)

    1. Hi,

      The reply I kept getting from the Atheist when trying to show that there is absolute truth, all he would keep saying when I would give examples of absolute truth was that he would say it is systematically true based on the system of logic.

        1. It was ages ago so I can try and find the debate but I believe it was saying all truth statements are systematically true, that is to say that truth statements are bound to the system of logic, so for example, if he said that there is no absolute truth and then I turned around and said well that is itself an absolute truth, he would say no that is a systemic truth. Or if I say that it is absolutely true that night follows day, he would say no that it is systemically true, meaning my statements are logical statements that are bound to the system of logic.

  6. “Cretans are always lying” – said by a Cretan (Quoted by Paul in Titus 1:12)

    “There is an exception to every rule.” (The statement is itself a rule.)

    “We arrived at religious views because it was evolutionary advantageous, not because it’s true.” (That view is not directly self-refuting, but the backup argument is that people believe what is advantageous rather than what is true; and that the reader should rather trust the views of the person speaking this statement, than their own religious views. But if people believe what is advantageous rather than true, why would this speaker’s views be true rather than merely advantageous?)

    “Safe abortions” (Safe gallows? Safe electric chairs?)

  7. How about, “Anything’s possible”? I hear that all the time. Of course, if anything is possible, it follows that it’s also possible that not anything is possible.

    1. Check out C.S. Lewis’ explanation of the possible vs. impossible in “The Problem of Pain” in the chapter “Divine Omnipotence”.

  8. That was all very interesting. Since this is, in a way, a Christian apologetics site, I think I’d like to point out that Hitchens’ oft-repeated “razor” is a self-refuting claim too.

    He asserted that “anything without evidence can be dismissed without evidence”. The problem here, is that he did not provide any evidence for such a claim, so by his logic, we can dismiss his statement as well.

    But of course, since I’m not a logician or anything of that sort, there may be an error in my observation or something

    God bless.

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