Appealing to authority: an expensive logical mistake

In everyday life, whether we like it or not, we rely on the information provided by experts or specialists. However, no authority deserves blind trust. When we take someone's word for granted simply because that person is an authority, we make the logical mistake called "appeal to authority."

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.

Circular arguments: a vicious cycle of faulty logic

A circular argument is an argument forming part of a thesis which has not been established, but still needs to be argued for.

Accurate statistics and faulty interpreters

Even the most rigorously researched statistics are not immune from misinterpretation, and they can often be used in a way that obscures the truth.

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.

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.

The appeal to novelty: How can it be faulty when it’s so bright and shiny?

To make an argument by appealing to the novelty of an idea— to the innovation it brings to a certain area—is not necessarily wrong. The visionary thinker Alvin Toffler coined the wonderful phrase nostalgia for the future, referring to his appreciation of the adventure the future promises through the desire many of us have to merge with 'the new' that is still developing...

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.

Slippery slopes and anxious feet

The fact that we are able to anticipate most of the consequences of our actions is undoubtedly a blessing. However, we can also allow fear or over-cautiousness to make us anticipate events that are not likely to follow. This edges us toward a common error of judgement: the slippery slope.

Two false oppositions: reason vs. faith and science vs. religion

"Intelligent, scientifically trained people no longer believe (or can no longer believe) in God."

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 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.

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.”

How to build valid arguments

Arguments must be convincing and, in order to convince, they must be valid—the minimum requirement of persuasion.

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.