Monday, August 2, 2010

Logical Fallacies Common in Everyday Life

If you want to make people feel that you know what you are talking about and win many arguments, a good way to do so is to learn about fallacies. I started looking into these after finishing a book called The Logic of Alice: Clear thinking in Wonderland by Bernard M. Patten (will be in the recommended books blog post), a chapter by chapter analysis of Alice's adventures through wonderland through a logician's point of view (which Lewis Carroll was, along with a mathematician). The first chapter was somewhere around seventy pages, and dealt almost exclusively with the simple phrase "down the rabbit hole" and its implications, but I digress. 

Logical fallacies are, as Wikipedia puts it, "misconception resulting from incorrect reasoning in argumentation." There are many fallacies, most have their own beautiful Latin name, that are employed often in a variety of arguments, ranging from the simplest dispute to debates amongst the most powerful people on Earth. Listed are some of my favorite ones to call people on:
  • Begging the question - Honestly, one of my favorites simply because I feel smugly superior when people make the grave mistake of saying "This begs the question:" followed by a question. Begging the question is one of my favorite fallacies to rant about, as John Nabn would vouch for this, because so many people do it. It can also be called a circular argument, and it simply means expressing a conclusion in such a way that assumes the conclusion. The conclusion can be true, but often times it is not, and this is where it is erroneous; yet in neither case is this a strong (or even correct) argument.
  • Non Sequitur - Literally translated from Latin, this means "It does not follow." An example from Wikipedia: 1) Men are human. 2) Mary is a human. 3) Therefore Mary is a man. Fallacies of this sort are common, and are oftentimes very easy to call. 
  • Post Hoc, Ergo Propter Hoc - A type of non sequitur, this fallacy relates to temporal relation of two or more events and draws, often incorrect, deductions from them. In very basic form, the argument goes similar to this: A comes after B, therefore B happened because of A. In this generalized form it is easily seen how this is false, and how easily counterexamples can be generated. 
  • Demanding Negative Proof - Another favorite of mine, this will appear in a later blog post regarding religion. For any claim, there needs to be evidence to verify the validity of the claim. Believers in a claim when confronted by opposition will often say, "prove me wrong!" This is easy when clear examples can be used to show the error, but many times this is impossible: "I believe in unicorns. Prove to me that they don't exist." The truth is, in our unicorn-less world, no one is able to show unicorns don't exist. If on the contrary we had a unicorn, we could clearly affirm the statement, and thus the opposition becomes wrong. More on this fallacy later.
  • Domino Thinking - This is common in politics: one person who opposes a measure explains a long chain of assumptions that lead to some unwanted event. Generally speaking, having many assumptions is a terrible idea. Here is an example: If marijuana is legalized people will be more likely to try harder drugs, causing a decline in society's morality, an increase in HIV (through infected needles), and an increase in violence. More on this subject later, but you can see the terrible, uninformed, overgeneralized conclusion that is drawn.
  • Reductio Ad Ridiculum - We all do this. When we are arguing, we use our opponent's argument in a way to make it sound ridiculous. From Wiki: 
    • "If Einstein's theory of relativity is right, that would mean that when I drive my car it gets shorter and more massive the faster I go. That's crazy! (This is, in fact, true, but the effect is so minuscule a human observer will not notice when it's observed on object without near-light speed.)"
  • Argument from Authority - This is an easily understood one. If someone makes a claim with no proof other than it is true because of an authoritative source, their argument is weak. "Doctors say to take asprin!" Why should we listen to the doctors who recommend asprin? Because they observed asprin's effects that are beneficial to humans, not because they are doctors! Make sure you know this one.
  • Ad Hominem - Also common in arguments, this fallacy tries to connect "the validity of a premise to a characteristic or belief of the person advocating the premise." Essentially, this fallacy is when someone attacks his/her opponent personally, and not their argument. This may not be wrong, but oftentimes it is.
  • Either-Or Arguments - For all but a few select cases, there are never just two answers to a problem. This fallacy is common in politics as well, as many politicians will use these to try to show how his/her opponent supports a position that will lead only to failure.

1 comment:

  1. Oh man, Alice books. Love this post right off the bat.

    Anyways, don't forget the "Novem Undecum" fallacy: