Ethical Realism

February 26, 2010

Four Terrible Ways to Argue

Philosophers have mentioned thousands of fallacies (errors in reasoning), but I will discuss four more in detail that I find to be very common. These fallacies are terrible ways to argue. I have already discussed several other fallacies, but here are four more that everyone needs to know about. Understanding these fallacies can help us develop better argumentation, and they can help us identify errors in reasoning given by others. The four fallacies are the following:

  1. Appeal to Ignorance
  2. Equivocation
  3. Reversal of Burden of Proof
  4. Begging the Question

1. Appeal to Ignorance

To say that something is true (or false) just because we don’t know something is an error in judgment. Consider the following argument:

  1. We haven’t found any alien life in the universe, even though we have spent some time looking.
  2. Therefore, we know there is no alien life in the universe.

This argument could be valid given an additional premise like the following:

  1. We haven’t found any alien life in the universe, even though we have spent some time looking.
  2. If we can’t find proof that something exists, then it doesn’t exist.
  3. Therefore, we know there is no alien life in the universe.

This argument is poorly reasoned. The view that proof is required for something to be true is clearly a false assumption. Such an assumption is often not one people generally have consciously, but their arguments occasionally imply such an assumption.

2. Equivocation

We need to use our terminology consistently. Sometimes a word has two different meanings, but it would be wrong to require an argument that requires us to use terminology inconsistently. Consider the following argument:

  1. I am logical because I know when I see an argument that sounds bad.
  2. Therefore, I don’t need to take a logic class.

This argument requires that ‘logical’ means “know what arguments sound bad.” However, that isn’t what logic classes are about. Logic classes are about teaching criteria used to evaluate reasoning.

Although this argument is obviously horrible, I suspect that almost everyone equivocates now and then. They don’t know what logic is in the philosophical sense, so they decide it isn’t needed.

Another common equivocation is to confuse “socialism” as “Marxism” with “socialism” as “Soviet totalitarianism.” Consider the following argument:

  1. Universal health care is socialistic.
  2. Socialism failed in the Soviet Union.
  3. Therefore, universal health care will fail.

The fact is that socialism in the sense of government programs (Marxism) is very common throughout the world. Public education is socialistic in this sense. Such programs occasionally are very successful. Universal health care has had relative success in various countries. Universal health care does not have to be anything like Soviet totalitarianism.

People often decide that logic is faulty, philosophy is unreliable, and communism has failed. These thoughts are often based on equivocating the terms. People think an argument is logical merely if it “sounds good,” philosophy means “my unsupported personal beliefs,” and communism means “Soviet totalitarianism.” This thinking infects our society at large and has caused all sorts of problems.

For example, philosophy and logic often aren’t believed to be worth teaching in high school. Without philosophy or logic it becomes utterly unclear what teachers think it means to teach critical thinking.

3. Begging the Question

One of the worst kinds of arguments beg the question. This means that someone uses controversial premises that make the conclusion trivial or that she uses circular reasoning. For example:

  1. We know God exists because the Bible says so.
  2. We know the Bible is reliable because God wrote it.

A premise of this argument requires us to accept that the Bible is reliable, but the conclusion is treated as evidence of that premise. The conclusion of an argument should not be used as evidence because it’s what we want to prove in the first place.

Another obvious example of a begging the question fallacy is the following:

  1. We have every reason to think marijuana should be legal, and no good reason to think it should remain illegal.
  2. Therefore, marijuana should be legal.

This argument fails to present the reasons we need to support the view that marijuana should be legal, but the premise does support the conclusion. The problem is that the premise itself is controversial (perhaps more so than the conclusion), and such a premise would make the conclusion trivially true.

4. Reversal of Burden of Proof

Every argument requires us to decide, “Who needs to prove something?” If one conclusion must be proven, then that conclusion has the “burden of proof.” If the conclusion is not proven, then we have reason to reject it. To misrepresent the burden of proof is a fallacy called the “reversal of the burden of proof.”

Consider the following argument:

  1. It is possible that there is life on Mars that we haven’t found yet.
  2. Therefore, we should believe in Martians.

This argument requires us to accept that people who don’t believe in Martians have the burden of proof. They need to prove that there is no life on Mars, but they haven’t done so. However, this is a misrepresentation of the burden of proof. If we want others to believe something exists, then we need sufficient evidence. We don’t have sufficient evidence that there is life on Mars at this time, so it is plausibly rational for us to disbelieve in Martians. It is also plausibly rational for us to reject the existence of ghosts, bigfoot, and unicorns considering that scientists don’t have enough evidence to confirm the existence of these entities (and that it seems likely that we would have been able to confirm their existence by now).


The fallacies mentioned here are serious errors in reasoning and we should keep them in mind to correct our thinking and identify fallacious thinking in others. To appeal to ignorance, beg the question, equivocate, or reverse the burden of proof is often to completely fail to give any reason to agree with our conclusion whatsoever.

(Updated 11/24/2013)


  1. […] (a) Know a little about what good arguments are. In particular, (i) formal logic, (ii) requirements of good arguments, (iii) justification, and (iv) terrible ways to argue. […]

    Pingback by How to Get an A in a Philosophy Class « Ethical Realism — March 3, 2010 @ 9:09 am | Reply

  2. […] them about formal logic, requirements for good arguments, justification, and fallacies. Tell them how these things are relevant to their lives and philosophy in […]

    Pingback by How to Teach Philosophy « Ethical Realism — March 5, 2010 @ 9:01 am | Reply

  3. “Many people argue that we should be undecided about whether or not God exists, which assumes that there is equal reason to believe in God as there is to disbelieve.”

    nahhh, people maintain that we should be undecided because it is impossible to prove a non-existence. That said, this quote from Dawkins is hilarious and quite applicable.

    “A friend, an intelligent lapsed Jew who observes the Sabbath for reasons of cultural solidarity, describes himself as a Tooth Fairy Agnostic. He will not call himself an atheist because it is in principle impossible to prove a negative. But “agnostic” on its own might suggest that he though God’s existence or non-existence equally likely. In fact, though strictly agnostic about God, he considers God’s existence no more probable than the Tooth Fairy’s.
    Bertrand Russell used a hypothetical teapot in orbit about Mars for the same didactic purpose. You have to be agnostic about the teapot, but that doesn’t mean you treat the likelihood of its existence as being on all fours with its non-existence.
    The list of things about which we strictly have to be agnostic doesn’t stop at tooth fairies and celestial teapots. It is infinite. If you want to believe in a particular one of them — teapots, unicorns, or tooth fairies, Thor or Yahweh — the onus is on you to say why you believe in it. The onus is not on the rest of us to say why we do not. We who are atheists are also a-fairyists, a-teapotists, and a-unicornists, but we don’t have to bother saying so.”

    Comment by Evan — August 19, 2010 @ 8:01 pm | Reply

    • I don’t understand why you present this as disagreement. I have talked about the teapot argument quite a bit in the past and it is compatible with what I am saying. “You can’t prove a negative” is compatible with “you can’t rationally believe in God.” In fact, the teapot argument is specifically designed to make that point clear.

      Comment by James Gray — August 19, 2010 @ 9:09 pm | Reply

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