What are examples of experts being wrong?

All people are mortal. Socrates is a human. Socrates is mortal. We also discuss this example under linear reasoning to show how an argument is made up. The first two sentences are premises which, with a logical deduction, lead to a conclusion: If he is a human being and all human beings are mortal, then one day Socrates will also die. This is a logical line of reasoning. But why? And which arguments are illogical or not when?

Fallacies are called arguments, that is, derivations of the abstract formula "From A (or A and A ') follows B" that are inconsistent or incorrect. There are various reasons for this, which can be divided into two categories: formal and informal fallacies.

Informal fallacies are, as the name suggests, wrong for no formal reason. Your premises are not correct. The derivation itself can be formally correct, but if one of the premises is factually incorrect, the argument will not fit either. An example:

All philosophers find Plato's allegory of the cave convincing.
Jacques Derrida is a philosopher. Accordingly, he finds Plato's allegory of the cave convincing.

Formally, there is nothing wrong with the argument. The mistake lies in the first premise, which is factually incorrect. This makes the whole argument obsolete.
Even if a premise is factually correct, a sentence sequence can still argue incorrectly or simulate an argument:

All philosophers are human. Derrida is a human and therefore also a philosopher.

Factually everything is fine here. But the argument is not logical. The conclusion does not follow from the premise: Derrida is not a philosopher because he is human (unless we extend the term philosophy so that all human speech and thought are philosophy).

Formal fallacies are the harder nut to crack because they are much better at hiding false arguments. Your problem lies in the fact that the formal derivation of an argument from the premises is either wrong or focuses on a third, mostly concealed category. We have collected examples to explain such formally incorrect deductions, such as natural arguments, compromise arguments or correlations as causality. All examples are fictitious.

Although it is necessary to pay attention to false conclusions and to avoid them, inconsistent or incompletely convincing deductions will creep in again and again. There are several reasons for this.

  1. On the one hand, every letter, especially scientific writing, is based on assumptions and hypotheses that can no longer be justified themselves. No scientific work can start from scratch and systematically justify everything in a formal and informal manner. It is helpful, however, to identify the assumptions made beforehand, i.e. the hypotheses that are not discussed further. For example, a paper that makes use of systems theory should mark this in order to delimit the following reasoning. Then a text can be better assessed and evaluated. Even if one argues that systems theory itself is problematic here and there, it should not be blamed on the work or the argument itself.
  2. Language in itself is not logical. It is the product of historically fine-grained developments and leads a life of its own. The meaning of the words, the signifiers, can never be clearly established because it only arises when it is differentiated from other signifiers. In principle, this makes language an unstable network of changeable meanings and also leads logical argumentation to its limits. The best examples of this are contradictions that still make sense (and thus somehow logical, although formally they are not).

To sort out the different fallacies, we used our colleagues from Skeptiker Schweiz, the Association for Critical Thinking, with their consent. Thank you at this point.