Non Sequitur: A forced conclusion is not really a conclusion

Needing to process a multitude of complex information in a short amount of time can lead to erroneous reasoning. When a conclusion is supported by weak or irrelevant arguments, the reasoning falls into the category called non sequitur—does not follow, or irrelevant argument.

Thinking as self-defence

No one has ever seen a thought, not even a neurosurgeon. However, today we know more about the way we think than what we were able to visualise, yet still less than we would like to know.

How to critically evaluate a text

Almost a century ago, writer Virginia Woolf noticed people’s tendency to approach books “with clouded and divided minds, asking fiction to be true, poetry to be false, biographies to be flattering and history to chime with prejudices.”

Erosion of trust | The ultimate effect of conspiracy theories

From television stories to personal experiences, we live in a world where honesty seems to be an increasingly rare commodity and suspicion and scepticism become protective shields.

Hasty generalisations: Jumping from one to all, and from once to always

We use our experience and knowledge to understand what is unknown or inaccessible to us. We are attracted to patterns and judge the world in terms of what is already familiar to us. However, out of a desire to understand some things more quickly, we often draw conclusions without sufficient evidence. Thus we fall into the trap of the sophism called hasty generalization.

Argumentum Ad Hominem or how you attack yourself when attacking others

In an argumentative discussion each party involved must be able to express their point of view without constraints, discrimination or other interferences. This is, in fact, an important prerequisite for the effort to overcome differences of opinion. In practice however, often things are far from this ideal. Not only do interlocutors not respect each other’s right to free speech, but they also resort...

The biased sample: why science should not be practised on friends

The biased sample is a kind of unrepresentative sample, either for quantitative reasons (as is the case with the too-small sample), or for qualitative ones, when its structure does not represent the structure of the real population that is the object of the research.

The false cause fallacy: Is dawn summoned by the rooster’s song?

From an early age I learned, from the advice of adults or from my own experiences—and sometimes the hard way—the relationship between cause and effect. It's simple: if you touch the hot oven door, you’ll get burned! Subsequently, I discovered that there are a multitude of pressing uncertainties all around us in daily life. To figure out what actually causes the things that...

The appeal to tradition or the risk of repeating history

In our everyday lives we ​​often resort to simply repeating what has been said or done before. But not everything that is old is authentic or correct. When we refer to tradition with full confidence that the way it was understood and acted on in the past is self-evident, we are committing the logical error of appealing to tradition, or false induction.

Reading polls: How do we evaluate surveys carefully?

Many news programmes, speeches, or press articles refer to at least one poll. When designed and conducted well, polls are an excellent means of measuring public opinion on a particular topic. Unfortunately, not all surveys are well compiled, relevant, representative, or honest.

Equivocation: Playing hide-and-seek in communication

When what someone says can be interpreted in multiple ways, we are in danger of coming to an understanding which is different to their intended message.

Appeal to popularity. What explains the popularity of an error?

When we consider that a conclusion is founded only if a lot of people consider it true, we fall into the trap of the argumentum ad populum or the appeal to popularity.

The most arrogant of all sophisms: the false accusation of logical error

In practice, people often accuse each other of making logical errors, but sometimes the accusation is false. Such an accusation is made by someone who does not understand what logical fallacies are and how they work, or by a manipulative person who takes advantage of the ignorance of those in the first category.

Appeal to hypocrisy: the trick of pointing the finger

When one wants to justify the harm one has done by saying that others have done the same or that this evil was only a reaction to the harm done by someone else, they commit the logical error of appealing to hypocrisy.

The small sample and the slender majority

In scientific research, sampling is the primary method used when research cannot be conducted on a one-to-one scale. The facts discovered at the level of the sample are presumed to apply in general.