This text analyzes the essence of identity, starting from the mathematical formula a = a. The author points out that identity is not a property of physical signs or real-world objects, as everything in the material world is subject to constant change and differentiation. Even two seemingly identical signs are distinct, just as a tree changes over time. Identity is therefore understood as the result of human abstraction and convention, where we consciously disregard natural inequality and the variability of things in certain contexts. The central point of the reflection is the assertion that identity does not reside in the objects themselves but in the act of meaning. It is the human subject who, through signs, refers to a meaning and establishes identity by ignoring non-essential differences. The text thus moves from formal logic to a deeper philosophical reflection on how human consciousness constructs stability in a changing world through semantic references and intentionality.