Dr. Mahtab Hossain Mazed

Today is Saturday World Logic Day 2025. An international day declared by UNESCO in collaboration with the International Council for Philosophy and Human Sciences (CIPSH) is observed on 14 January every year in November 2019. It was first celebrated on 14 January 2019 before the UNESCO declaration. World Logic Day seeks to draw attention to the intellectual history, conceptual significance, and practical implications of logic to the interdisciplinary scientific community and the wider public.
> What is logic?
The English word logic is derived from the Greek word logike. The word logike is again an adjective from the Greek word Logos. Logos means thought or language. So logic in the literal sense is the science of thought expressed in language. It should be noted here that the word 'thought' is very widely used in psychologyBut by 'thinking' in logic, we understand only hypothesis. Since man can think, the curiosity to know the unknown from the known is eternal. The mental process of knowing the unknown through knowing is called inference. And the science which deals with inference and its supporting processes is called logic. That is, the practical science which avoids fallacy and regulates reasoning or inference and its auxiliary processes for the purpose of attaining truth is called logic.

> What is logic
Logic is the science of thought expressed in language that prescribes the rules of correct thinking and how to follow those rules to make our thinking correct and true.

> Document definition:

As there is some disagreement among logicians about the nature of logic, they have defined logic in various ways. The notable definitions are:

According to Joseph, “Logic is the science of thinking.”
Wheatley said, "Logic is the science and art of reasoning."
According to Thomson, "Logic is the science of the rules of thought."
Hamilton said, "Logic is the science of the formal rules of thought."
According to Aldrich, “Logic is the art of reasoning.”
"Logic," said Welton, "is the science which governs the principles of valid thought."
None of the above definitions are absolutely wrong. However, most definitions are narrow, vague, vague, or overly broad. has given the most acceptable and satisfactory definition of logic

J. S. matching In his definition, he says, “Logic is the science of those processes of thought,” which processes depend on evidence; That is, the process of arriving at the unknown truth from the known truth and all the other processes related to it.Finally, in the definition of logic, it can be said that the science which helps to apply sound reasoning and avoid false reasoning with the help of logic and its related processes is called logic.

> Father of logic
Aristotle is called the father of logic.

Although Plato did not discuss logic directly, his student Aristotle received his basic instruction in logic from Plato. Logic was one of the most important subjects in Plato's proposed system of education. And Aristotle made that logic a reality. This is why Aristotle is called the father of logic.

Ancient Greek philosopher and philosopher Aristotle is called the father of logic. He first developed a formal system for logic and made many important conclusions in early Greek logic. Aristotle was born in 384 BC and died at the age of 62.

> What are the types and types of logic?

Argument can be divided into two parts. For example, 1. Deductive 2. Inductive

> Deductive
Arguments in which the conclusion necessarily derives from one or more propositions and the conclusion can never be broader than the proposition; That logic is called deductive logic or inference.

For example;

Motto: All men are mortal.

Proposition: Mr. Rahim is a man.

Refrain: So, Mr. Rahim is mortal.

Here the conclusion is inevitably derived from the argument and the conclusion is no wider than the argument. That is, from these arguments or premises, the conclusion is only that "Mr. Rahim is mortal" and nothing else. In this logic, since the conclusion has an inevitable relationship with the premise, if the conclusion is true, then the conclusion is bound to be true or valid. And if the argument is false then the conclusion is bound to be false or invalid.

> Inductive
Assumptions that form an overall synthetic argument based on observations of particular instances are called ascending arguments or inferences. For example;

Asylum: All swans in Asia are white

Motto: All swans in America are white

Asylum: All swans in Europe are white

Conclusion: All swans in the world are white.
Here we have observed the swans of Asia, America and Europe, not all the swans of the world. That is, we observe particular examples and find that they are all white. And based on this particular observation we have come to the conclusion that all swans in the world are white. These arguments cannot be guaranteed. Because if the observation changes, the decision will change. So these arguments are plausible. If we ever see a black or any other color swan then our judgment will be false.

> What does logic mean?
We know that thought and language are inseparable. We always express our thoughts through language. So the original meaning of logic is the science of thought expressed in language.

Aristotle's concept of logic:
Aristotle called logic the early science directing the method of knowledge. According to him the function of logic is to prescribe the method of knowledge. Every branch of knowledge, be it art or science, follows certain rules and principles. And logic, as the science of thought, provides the rules for these. The function of logic is to indicate how a thought or discussion can be expressed in the right way or to tell how it can be called valid or invalid if it is raised. That is why Aristotle made this comment about logic.

JS Mill's concept of logic:
JS Mill made unique contributions to logic and ethics. He thinks that the two branches of logic, descending and ascending, are the rules of searching for true knowledge. According to him, descending logic adjusts our search for being in the light of established truths, and the ascending logic of science provides us with the necessary rules for discovering things. Mill defines logic in his book A System of Logic. Logic is the science of managing our cognitive processes that deals with the mental processes and mental processes of intellectual action necessary to arrive at truth from known truths through judgment or proof.

Joseph's concept of logic:
British professor Horace William Brindley Joseph tried to define the nature of logic in his book A Introduction to logic. Joseph held that logic as a science explains the principles of its own discourse. For example, logic deals with rules of definition, principles of logical division, rules of inference. According to Josephus, logic is the science that deals with the general rules of thought.

I. M. Concept of Logic of Copy:
American professor Irving Marmer discusses logic by considering the original work of copy logic. Cope believes that logic can be used in every aspect of life. The lessons of logic help us distinguish pure from impure logic, advance the pursuit of knowledge, and help us understand any subject of interest. Logic expands and actualizes our intellectual abilities. Logic helps in formulating acceptable and pure arguments in all fields.

> The idealism of logic is manifested in the following aspects:

Logic does not analyze facts or events, but only the analysis of thought processes and reasoning.
Logic does not determine the nature or form of a thing, but explains how it conforms to particular ideals.
The purpose of logic is to find truth and avoid fallacy, so it formulates and analyzes ideal arguments that correspond to real-world issues.
For example, logic deals with how an argument is valid if it fulfills its conditions. It does not analyze any facts or events, but only logic. Logic does not discuss whether an argument would be true in the real world if its conditions were met, but only whether the argument would be normatively valid.

Thus, based on the above discussion, it can be said that logic is called an idealistic science because it does not discuss the nature or nature of a subject, but explains how that subject conforms to a particular ideal.

> What are the types of logic words?
In logic, words are divided into three categories, namely: predicates, predicates and predicates. On the other hand, in the light of logic, terms are only of two types. Namely: objective and conditional terms.
Finally, logic is called the science of all sciences. Why logic is called an idealistic science is because it does not discuss the nature or form of a subject, but explains how that subject conforms to a particular ideal. The basic ideal of logic is truth. Logic deals with the purpose of finding truth and avoiding error through the application of correct thinking and reasoning.

Author, columnist and researcher
Founder and Chairman, Jatiya Rogi Kallyan Society.