# What is the Principle of Identity, Examples of the Principle of Identity

July 2, 2021 Off By Felso

The principle of identity is one of the three basic principles of Aristotle’s formal logic: Identity, non-contradiction, the impossibility of the third state.

Identity is also expressed in various idioms:

A thing is what it is
Everything is identical to itself,
what is right is always right,
A proposition cannot be true and false at the same time (either true or false),
A is A.
WHAT IS THE IDENTITY PRINCIPLE?

Identity; Unlike the concepts of similarity and equality, it is the principle of logic that states that something is identical with itself. According to the principle of identity, as long as the meaning of a proposition does not change, its truth value always remains the same.

For example; “Student is student.” In the proposition, the meaning of the term student is always the same at the beginning and at the end.

According to the principle of identity, every concept and proposition in a reasoning must be the same as itself and must be nothing other than itself. A thing is what it is. In this context, the principle of identity is expressed in the symbolic language as A ⇒ A (A if A).

For example;

All people are brothers.
Turks are people.
So, Turks are brothers.

During such reasoning, the concept of sibling can mean different things. However, in accordance with the principle of identity, we need to use the concept of sibling in the same sense in the continuation of the reasoning, in the sense that we used it when we first used it.

In the above example, since the concept of brother is used in the sense of friendship, friendship, not being an enemy, it must be used in the same sense in the continuation of the reasoning.

The principle of identity is in itself an inadequate reasoning principle. The principles of non-contradiction and the impossibility of the third state, which are the other principles of thinking, complement the principle of identity as well as form the basis for the principle of non-contradiction and the impossibility of the third state.

Related topics:

What is the principle of non-contradiction?
What is the principle of impossibility of the third state?
DIFFERENT APPROACHES TO THE PRINCIPLE OF IDENTITY

Aristotle expressed the principle of identity, together with the principle of non-contradiction, in his work “Organon”: “The same thing cannot exist and not exist in the same phenomenon, at the same time and in the same respect.” In this case, it can be said that “he who affirms or denies speaks the truth”.

Leibniz developed this complex formula of Aristotle and clarified it with the “principle of the identity of the indistinguishable” and put it forward as one of the basic principles of formal logic.

This principle is used in the field of abstract and formal logic. However, metaphysicians have taken this principle, which should be specific to the field of abstract logic, to the field of objective reality, and have drawn wrong conclusions from it that objects and facts are immutable.

Bourgeois philosophy also made use of these metaphysical false conclusions as much as possible and argued, for example, that capitalist society is unchanging and unalterable. However, just as capitalist society was a feudal society a while ago and a slave society before that, it will turn into a communist society (socialism) after a while.

In the field of objective reality, motion and change are fundamental, no object and phenomenon, whether natural or social, can remain identical with its own cat. Engels writes in his “Dialectic of Nature”:

“In fact, even in inorganic nature there is no such identity. Every body is faced with mechanical, physical and chemical effects that constantly change it, transforming its identity into new forms. The change of concrete identity is proved in every detail by the natural science it contains. Abstract identity, like all metaphysical categories, is valid in everyday practice where small measures or short periods of time are involved… identity and difference are two fundamental oppositions that transform into each other.”

Prepared by: Sociologist Ömer Yıldırım