• Home
  • About
  • About Theme
  • Events
  • Contact
  • Sponsors
  • Blog
  • How to spot bad logic, TED or otherwise.

    Humans like to argue. A lot. Argumentation forms the basis of not only our dinner table conversations, (or the majority of our interactions with our SOs), but is arguably one of the main drivers of human progress.

    It is easy to see why. Debate and discussion is a great way to contrast perspectives, weigh alternatives, and discover the best ideas. It is this synthesis and filtering of knowledge that allows us to ultimately build successful civilizations. It is even said that the vast Roman empire was forged in its Senate and that the Navaratnas in Akbar’s Court were the true masters of the realm. If you’d like to read more about this, I highly recommend Barry Allen’s Knowledge and Civilisation.

    At an only slightly smaller scale, all TED and TEDx talks are in essence arguments made in favor of a novel idea. Chimamanda Adichie’s talk on why we should all be feminists, for example, is an argument in favor of making fundamental changes to our thinking for the sake of a fairer society. And then there is your annoying little brother whose go-to argument when he’s criticized is “Jo bolta hai wahi hota hai”.

    Regardless of their scope and scale, it is obvious that a large fraction of arguments are flawed. Bad reasoning seems to be the bread and butter of much of political and media discourse. It can thus be very difficult to wade through the ocean of information available to us (thanks, the Internet) and determine which claims are reasonable and which aren’t. But since when have overwhelming odds stopped us TEDxers?

    As a starter kit, we present to you the four most common logical screw-ups people tend to make, a.k.a logical fallacies, (with their fancy Latin names in parentheses)


    Let’s get technical for a bit. A correlation occurs when two variables seemed to be statistically linked, such as the level of caffeine in your bloodstream and your heart rate. As one increases so does the other.

    A causal relationship between variables occurs when a change in one variable causes a change in another, by a well-understood mechanism. In the coffee example, the causal mechanism is that caffeine’s chemical structure stimulates the release of the hormone adrenaline, which then elevates your heart rate.

    The point here, however, is that correlation does not imply causation. The fact that two things are statistically linked does not mean that one causes the other. The most hilarious example of this I’ve ever come across is this

    As clearly seen from the graph, a decrease in the number of pirates in the sea correlates with an increase in the global average temperature. Does this mean that pirates are the solution to global w’arrrrh-ming?

    No. The 1800s saw industrialization on a huge scale, as well a trend of pirates finding alternative careers involving less killing and sea sickness. As the pirates dwindled and the globe warmed, we found a fantastic opportunity to draw a nice graph.


    This one is unfortunately very common in political discourse. It involves attacking the person making the argument, rather than the substance of the argument itself. This is usually done by attacking the character of a person, or implying that he has ulterior motives which prompt him to make that argument.

    The thing is, arguments (especially those rooted in empirical facts) exist more or less independently of the person making them. The identity or inclinations of the person making the argument are irrelevant.

    Take for instance the reactions to (former RBI governor) Raghuram Rajan’s comment that India’s place as the world’s fastest growing economy was merely a case of “A one eyed king in a kingdom of the blind”. As this remark was construed “Anti-National” by some commenters, questions were raised about his true “patriotism” and whether or not he was working in the national interest. In fact, a noted politician even went to the extent of saying that Rajan wasn’t “fully mentally Indian”, presumably referring to the fact that the ex-governor held a US green card.

    Rajan made the “one-eyed” comment taking into account the state of the global economy and using his expertise in economics. Questioning his nationality or criticizing his lack of patriotism is by no means an effective rebuttal, and only serves to distract the debate.


    This one is easy to explain: the fact that a large number of people believe something is true does not make it true. A classic example is the case of Galileo Galilei. In the early 17th century, Galileo was perhaps one of a few dozen people in Europe that believed that the Sun was the center of our celestial system, and all the other planets revolved around it. The entirety of Europe, or perhaps even the world, scoffed at the idea, pointing out the obvious fact that it was the Sun that moved in the sky. In fact, in 1642, he was sentenced to life imprisonment by the Catholic church for his “heretical” idea. In 1992, around 350 years later, the Vatican finally admitted its mistake in a formal statement by Pope John Paul II. Rather Gali-late, I’d say.


    This is the simplest and most infuriating type of fallacy: the argument just makes no sense! The conclusion simply does not follow from the premise.

    If you ever figure out what someone’s preferred language has to do with their attachment to their parents, please let us know in the comments.

    Or comment anyway, we’d love to hear from you.

    Mayank Mallik
    TEDxNITTrichy Speaks!