The word fallacy comes from the Latin word fallacia, which means “deception.” It is used in the field of logic and rhetoric to designate those arguments that seem valid at first glance but are not.
That is, it is a form of erroneous reasoning, which can be committed innocently or to manipulate others since although its internal logic is wrong, it can still be emotionally or psychologically effective.
Now, that an argument is not valid (that is, that it is fallacious ) does not mean that its premises are necessarily false, nor that its conclusions are either. It simply means that the reasoning that connects to the premises and conclusions is wrong, flawed. In this sense, the fallacies are procedural errors, and not so much content.
Fallacies have been studied since classical antiquity, especially Greco-Roman. Philosophers such as Aristotle (384-322 BC) gave great importance to logic, and in their Sophistic Refutations, the subject is comprehensively addressed, managing to identify thirteen different fallacies, organized into two groups: those whose invalidity depends on the language, and those in which not.
Since then a significant number of fallacies have been added to the list, usually identified by a name that embodies their illogical reasoning mechanism. Here we will see some examples.
Examples of fallacies
1. The straw man fallacy
Also known as the “scarecrow fallacy”, it consists of the caricature, misrepresentation, and exaggeration of the adversary’s arguments, to take them out of context and make them easier to refute, which would not happen if we face them through true logical reasoning.
Its name comes from the fact that the formerly straw dolls were used to train soldiers in combat since the former are immobile and easy to bring down.
For example, let’s imagine that someone advocates the legalization of abortion, arguing that it is a fact that already occurs in society and that it requires certain controls. Another person may try to refute that argument by accusing you of wanting to legalize robbery and murder later.
The problem is that the fallacy does not logically confront the arguments in favor of abortion that are put forward, but rather invents arguments that are easier to combat and attacks them, attributing them to its opponent.
2. The sniper fallacy
This fallacy gets its name from an anecdote, real or not, in which an alleged sniper fired several times at a barn in Texas, United States, and later drew a target on its surface, to make it appear that each shot had been perfectly planned, thus demonstrating his skill with the rifle.
Similarly, whoever uses this fallacy makes up, adjusts, or manipulates the information to produce a posteriori meaning, and it seems that everything is the product of a logical conclusion, finding patterns where there are none, at convenience.
Suppose someone walks at night and finds a bill on the ground. He takes it and looks up, and it seems to him that the stars form an arrow pointing towards the bill, so he decides that whoever follows that arrow will get free money. When someone doubts that this is true, they show them the ticket found as evidence.
A single event does not serve to determine a pattern, and the existence of the money found does not automatically prove its causes, as the targets painted by the sniper do not show that he has good aim.
3. The ad hominem fallacy
Its Latin name means “against the man” and it means that, instead of fighting the ideas of the argument, the person who proposes them is fought, thus rendering them invalid through non-logical reasoning. It is an extremely common fallacy in different areas of debate, especially in politics, in which it is common to publicly distort an individual to also distort his ideas.
For example, suppose that a politician proposes a new tax law, and instead of fighting what the law proposes using arguments that have to do with tax, politics, or economics, his opponents respond by accusing him of beating his wife.
Whether or not this last accusation is true, by itself it says absolutely nothing about the tax law and therefore does not serve to oppose it, since the popularity or morality of the person proposing it is irrelevant.
4. Fallacy of hasty generalization
It consists, as its name indicates, in an extrapolation or generalization procedure that is not supported by logical premises, but is given arbitrarily, that is, without having sufficient evidence. Generally, these generalizations lead to bad inductions and erroneous conclusions, so we can consider it fallacious inductive reasoning.
Let’s imagine, as an example, that someone adopts a cat, and that their pet shows a fondness for eating chocolate. Then, quickly generalizing, the person decides that cats like chocolate, without stopping to think that perhaps it is only their cat that likes chocolate, or that perhaps some cats like it and others don’t.
Formal and informal fallacies
Over time, fallacies have been classified in very different ways, the first being the one we mentioned at the beginning, the work of Aristotle. However, more common today is the classification that distinguishes between formal and informal fallacies.
- Formal fallacies. They are those whose invalidity can be demonstrated by reviewing the forms, that is, the logical procedure itself, through validity tests.
- Informal fallacies. They are those whose invalidity does not lie so much in the formal, that is, in the reasoning method, as in the content of the arguments or the intention with which they are formulated.
Fallacies and sophisms
The difference between fallacy and sophistry was common in the past, but today it is in disuse. It was based on the intentions of the person carrying out the invalid reasoning. So if this person has no intention of lying, but is simply wrong, we are in the presence of a fallacy.
On the contrary, sophistry exists when a fallacy is emitted with malicious intent, that is, knowing the logical error. However, it is not always possible to determine a person’s intentions from what they are saying, so this differentiation may not be as helpful as it initially appears.