law of identity
C2Academic, Technical, Philosophical
Definition
Meaning
A principle in logic and philosophy stating that a thing is identical to itself. Formally expressed as A = A.
A foundational axiom in classical logic and philosophy, often considered the first of the three classic laws of thought. It asserts that an object or concept is the same as itself and possesses a consistent, definable nature.
Linguistics
Semantic Notes
Primarily a term of art in logic, philosophy, and sometimes in legal theory. It is used to denote a basic principle of rational thought. Not used in everyday descriptive language.
Dialectal Variation
British vs American Usage
Differences
No significant differences in usage or spelling. The term is uniformly technical.
Connotations
Identical academic and philosophical connotations in both varieties.
Frequency
Extremely rare in general discourse, appearing with equal low frequency in specialised texts in both regions.
Vocabulary
Collocations
Grammar
Valency Patterns
The [law of identity] is fundamental.[Subject] violates the [law of identity].According to the [law of identity], [proposition].Vocabulary
Synonyms
Strong
Neutral
Vocabulary
Antonyms
Usage
Context Usage
Business
Virtually never used.
Academic
Core term in logic, philosophy, and critical thinking courses. Used in discussions of foundational principles.
Everyday
Extremely rare. Would only appear in advanced discussions about philosophy or logic.
Technical
Standard term in formal logic, analytic philosophy, and metaphysical discourse.
Examples
By CEFR Level
- The philosopher explained that the law of identity means a thing is what it is.
- Critics argued that the theory's central premise seemed to violate the fundamental law of identity, leading to logical inconsistencies.
- Before delving into complex paradoxes, one must first accept the axiomatic truth of the law of identity: A is A.
Learning
Memory Aids
Mnemonic
Think: "A thing is itself. A cat is a cat. That's the law!" The word 'identity' reminds us a thing is identical to itself.
Conceptual Metaphor
LOGICAL FOUNDATION IS A LAW (as in a law of nature or a legal statute).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'закон об идентификации' (a law about identification). The correct equivalent is 'закон тождества'.
- Avoid translating 'law' here as 'правило' (rule); in this philosophical context, 'закон' (a fundamental, immutable law) is correct.
Common Mistakes
- Using it to mean a legal statute concerning personal ID. / Confusing it with the 'law of non-contradiction'. / Attempting to use it in everyday descriptive sentences (e.g., 'The law of identity of my car is red.' – incorrect).
Practice
Quiz
In which field is the term 'law of identity' primarily used?
FAQ
Frequently Asked Questions
No, it is not a statute or legal rule. It is a principle of logic and philosophy, one of the foundational 'laws of thought'.
It is traditionally attributed to Aristotle, who systematized the laws of thought, though the concept is implicit in earlier philosophical reasoning.
It is most simply and commonly expressed as the logical formula: A = A.
Almost never. It is a highly specialised term confined to academic discussions in logic, philosophy, and related technical fields.