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.
Everything relevant to know about the irrelevant conclusion
What we call an “irrelevant conclusion” is an argument that gives the impression of having something to do with an idea it aims to support, but which actually shifts attention to something else.
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.
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.
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...
Appeal to ignorance: Why it is useless to hide behind your finger
The appeal to ignorance (argumentum ad ignorantiam) is an error in thinking which argues that a conclusion is true because there is no evidence against it, or that a conclusion is false because there is no evidence in its favour.
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.
The applications and pitfalls of critical thinking
Critical thinking is not a cure-all, but it proves very useful in dealing with, clarifying, and solving some decision-making problems, as well as the thought and belief disputes which occupy our minds.
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.
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.
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...
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.
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.
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."
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.


























