WHAT IS MATERIAL LOGIC? - PHILOSOPHY - 2025

The materials logic is a branch of logic which analyzes the content of its premises, in contrast to formal logic, which only studies the structure of propositions. It is also known as applied logic as it is designed to lead to a logical conclusion that is useful in the real world.

Traditionally, there are two main branches of logic: formal logic (also known as minor logic) and material, applied or major logic. Although the bases of both types of logic are similar, the problems they deal with are totally different.

Some scholars also speak of a third type of logic, informal logic, which would be responsible for studying the correct ways of reasoning but taking into account the context and content of the arguments and propositions.

History of logic

The word "logic" comes from the ancient Greek "logike", which means "intellectual or argumentative". It can also come from the word "logos", which means "word or thought."

Logic is the branch of philosophy that is responsible for studying the forms of reasoning, and their validity. It is one of the two formal sciences, along with mathematics, since it does not have a content based on the real world: it only deals with valid forms of inference.

In other words, logic is the science that is responsible for studying what distinguishes the correct reasoning from the incorrect.

Its main mission is to discover the laws of human thought, as well as the methods that we can use so that our thinking leads to correct conclusions.

Types of logic

Although logic always studies the relationships between different elements or "propositions," it can do so in several different ways. Traditionally, there are two types of logic:

• Formal logic, also known as pure logic. It is responsible for determining what are the correct and valid ways of thinking and drawing conclusions.
• Applied or material logic, in which not only the way to draw conclusions is analyzed, but the content of the premises itself, in such a way that in the end a result that is in accordance with reality has to be achieved.

Differences between formal logic and material logic

Formal logic is responsible for the abstract study of deductive propositions, phrases and arguments. This discipline extracts from the content of these elements the logical structures that form them. Once this is done, it is studied whether the argument is valid through syllogisms, or through pure logic (substituting symbols for propositions).

However, although an argument may be valid at the logical level, this does not imply that it is true. For example, the following syllogism can occur:

• No man does wrong
• This criminal is a man
• Then this criminal does no wrong

Although from the point of view of formal logic this argument would be valid (because the conclusion can be drawn from its premises), it is clear that the conclusion is not true in the real world.

This is precisely what applied logic is in charge of: studying whether the conclusions drawn through formal logic are true in the real world or not.

Argumentative fallacies

One of the fields that is in charge of studying material logic is that of argumentative fallacies. These are arguments that appear to be logical, but which, once carefully examined, turn out to be false.

These types of arguments are widely used in everyday discussions. Therefore, their learning is very useful to learn to argue more effectively.

Despite the fact that there are many types of argumentative fallacies, and that some are within formal logic, we will now see some of the most common types that applied logic is responsible for.

1- Fallacy ad ignorantiam

This argumentative fallacy consists of trying to show that something is true simply because it cannot be known for sure that it is false. One of the most curious examples of this type of fallacy is that of the "Flying Spaghetti Monster religion", which a university professor invented.

It is a false religion in which an invisible monster made of spaghetti and meatballs is worshiped, and who created the universe in his image and likeness.

The main argument to prove its existence is that "we cannot know for sure that it does not exist."

2- Ad consequentiam fallacy

This fallacy consists of trying to convince the interlocutor that something is true or false depending on whether the consequences are good or bad.

To say that bread is not fattening because that would be a serious blow to the farmers' economy would be an example of this type of fallacy.

3- Fallacy ad verecundiam

This type of fallacy, also known as the "authority fallacy," consists of pretending that a conclusion is valid only because it is defended by someone of great importance, either because of their knowledge or because of their social position.

An example of an ad verecundiam fallacy would be to pretend that the Earth is flat because a famous person says it.

4- Fallacy of hasty generalization

It is based on jumping to conclusions without having enough data to confirm it. The classic example is stereotypes: beliefs about people of certain races, sexual orientations, nationalities or genders, stating that all those who belong to those groups are in one way.

For example, the belief that all Andalusians are lazy and Catalans stingy is a hasty generalization.

5- Ad hominem fallacy

This fallacy consists of rejecting a person's arguments as false because of a personal characteristic. For example, rejecting someone's ideas because they do not have a good self-image, because they speak strangely or because they do not have pleasant features.

6- post hoc ergo propter hoc fallacy

This fallacy (which literally means "after, therefore because of") consists in believing that if one event happens right after another, both have to be directly related, despite the lack of evidence to affirm something like that.

For example, if someone touches their lucky charm before playing the lottery, and wins, they can argue that they have won the prize precisely for taking that action previously. This would be a post hoc ergo propter hoc case.

References

1. "Introduction to logic / What is logic?" at: Wikiversity. Retrieved on: January 17, 2018 from Wikiversity: es.wikiversity.org.
2. "Formal logic" in: Britannica. Retrieved on: January 17, 2018 from Britannica: britannica.com.