Logical fallacies are mistakes people make when they argue. These mistakes can be in the form of an argument structure, vocabulary, or context.
Many of these fallacies are due to an inability to understand or apply formal logic. While formal logic is a set of rules that define how to construct a valid argument, informal logic is how people naturally argue.
Unfortunately, many people do not know the rules of informal logic, so they end up arguing based on flimsy points and non-existent evidence. This leads to many flawed arguments that seem very convincing.
This article will discuss some of the most common fallacies and how to spot them. By being more aware of these errors, you will become a more critical and logical thinker.
Example of syllogism
A syllogism is a logical argument consisting of a major premise, a minor premise, and a conclusion. A syllogism follows the format of “all As are Bs, allCs are As, therefore all Cs are Bs.”
In this example, the first sentence is the major premise, “All men are doctors” is the minor premise, and “some doctors are tall” is the conclusion.
As you can see, this syllogism is flawed because the second sentence (“some doctors are tall”) does not agree with the conclusion (“all doctors are tall”). This is an invalid syllogism!
There are many different ways to construct a valid syllogism. One way is to make sure both sentences in the minor premise agree with the conclusion.
Weakness of syllogism
Unfortunately, this kind of syllogism is considered valid, which is why so many people fall into this trap. But just because there are certain characteristics that doctors have in common, and that some men do not have certain characteristics, it does not follow that some men are tall.
The problem lies in the fact that syllogisms only state necessary conditions for a conclusion to be true, they do not prove the conclusion to be true.
In other words, just because some men are doctors and some doctors are tall, it does not follow that some men are tall. That conclusion can only be proved if other necessary conditions are met.
The problem with most people who fall into the weakness of syllogism error is that they assume the necessary conditions for the conclusion to be true are met when they are not.
A strong syllogism
The argument you’re making is strong. A syllogism is a structured argument that has three parts: a major premise, a minor premise, and a conclusion.
The major premise is the big statement you’re trying to prove. The minor premise is a smaller statement that supports the major one. The conclusion is what you want people to take away from your argument.
In this case, the major premise is men are doctors, the minor premise is some men are tall, and the conclusion is therefore some doctors are tall. The fact that so many people seem to fall for this fake syllogism shows just how convincing it is!
If this seems confusing, don’t worry – we’ve broken it down for you. Read on to learn more about how to identify a strong syllogism and how to spot a weak one.
Examples of a weak syllogism
A syllogism is considered weak or faulty when one of the major premises or the conclusion does not fit with reality. For example, the following syllogism is incorrect:
If some men are doctors and some doctors are tall, then if you are a man, you can be a doctor.
This statement is incorrect because it assumes that all doctors are men. Since this is not the case, this statement is false and cannot be proven true.
The term “if…then” in logic refers to the assumption that something is true, followed by something that follows from that assumption. In the above example, the first sentence contains the “if…then” structure and assumes that all men are doctors. The second sentence contains the “then” part of this structure and states that all people who are doctors are tall.
Examples of a strong syllogism
A strong syllogism is one that does not contain any errors. There are two major categories of errors:
Errors in the major premise (the first statement)
Errors in the minor premise (the second statement)
If either of these statements is false, then the conclusion cannot be true. A syllogism is only as strong as its weakest premise!
There are several ways to check if a syllogism is valid. The most common method is to rearrange the statements and then ask if the conclusion follows from the premises. If it does, then it is valid!
For example, try testing out this argument: All men are humans, all humans are mortal, therefore all men are mortal.
In real life, it is difficult to make strong syllogisms
Syllogisms are one of the major theories of how we understand and learn new information. Most formal educational systems require some form of syllogism learning, usually in elementary school.
Syllogisms are logical statements that have a major premise, a minor premise, and a conclusion. They typically look like this:
Major Premise: All X are Y
Minor Premise: A is X
Conclusion: A is Y
This syllogism is valid because both the major and minor premises are true – in other words, all doctors are people, and Alice is a person, so Alice is a doctor. This example is an A→C→A syllogism (A = Alice), but there are also C→A→C syllogisms (Alice → Doctors Are People). ←(Doctors Are People)←|>|>|>|>|>|> > > > > > > > ^ ^ ^ ^ ^ ^ ^ ^^ ^ ^ ^ The opposite can’t be true- for example, not all doctors are people cannot be concluded from the fact that Alice is a doctor. >>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> In formal logic courses (and in some middle school curriculum), students learn how to make these valid syllogisms using three simple rules. First, you must have two statements (the major and minor premises) that are related by either “all” or “some”; second, the middle term must be common to both premises; third, the conclusion must be in the same direction as the major premise. These rules make it easier to identify whether or not a syllogism is valid! >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> However, these rules do not work if you try to apply them after the fact- you have to find out if a syllogistic statement is valid before you can use these rules. You have to spot the pattern before you can break it down into simple steps.
Unfortunately for us laypeople with no formal logic training, most of us end up making invalid inferences on a daily basis.
How many times have you heard someone say something like “If A then B” and then later heard something like “Not A therefore Not B”? Many of us would respond with something like “Well I know that If A then B!” But in reality we don’t- we only think we do.
In this article I will explain how to determine whether or not an inference is valid using two simple rules.
The first rule states that if either premise or the conclusion contains words such as all or none then the inference cannot be proven.
All men are atheists until pushed to faith by hard evidence
Faith is belief without evidence. Most people believe in something, whether it’s a god, ghosts, astrology, tarot cards, reiki, chakras, crystals, veganism, etc.
Many people believe in a universal force or god that controls everything. But how can you know for sure? You can’t unless you see the whole universe and control it.
You can only know what happens in your limited sphere of experience. You cannot know what happens outside of your own experience—you can only guess. Guesses may be based on evidence and faith is sometimes defined as “confidence in something uncertain.” But still—it is an uncertainty.
Many people have faith in God because they have experienced things that they cannot explain or understand rationally and so they assume there must be a divine cause for them.
Intelligence and cognitive function are strongly associated with height
Many studies have found a strong correlation between height and intelligence. A 5-year-old child who is tall is likely more intelligent than a similarly aged child who is of average height but less intelligent.
These studies typically examine the IQ scores of children, but also find a correlation between height and higher IQ in adults. Adults who are taller are more likely to have a higher intelligence level than those who are of average height.
Why Does This Matter?
For many people, the idea that physical appearance might have anything to do with intelligence is disconcerting. It can make people uncomfortable, and it may even keep some people from paying attention to important issues that really matter when it comes to quality of life.