numerical identity
C2Formal; primarily academic, technical, philosophical
Definition
Meaning
A concept from logic, philosophy, and mathematics meaning that two things are not merely similar or equivalent but are literally one and the same object; strict sameness.
In broader technical use, it can refer to a unique identifier (like an ID number) that designates an entity as distinct from others within a system, establishing its singularity and continuity.
Linguistics
Semantic Notes
It is a compound technical term. The phrase often functions as a singular noun phrase. It is not about numbers being identical but about identity established by being numerically one (i.e., "one in number").
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. The term is international academic jargon.
Connotations
None beyond its technical precision.
Frequency
Equally rare in both varieties, confined to specialised discourse.
Vocabulary
Collocations
Grammar
Valency Patterns
The [noun phrase] establishes the numerical identity of [entity].A key issue is whether [X] and [Y] share numerical identity.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “[None for this technical term]”
Usage
Context Usage
Business
Rare. Possibly in data management: 'The social security number provides a numerical identity for each citizen in the tax system.'
Academic
Primary context. 'Leibniz's Law is fundamental to discussions of numerical identity in metaphysics.'
Everyday
Extremely rare. Not used in casual conversation.
Technical
Used in philosophy, logic, computer science (object identity), and legal/registration systems.
Examples
By Part of Speech
verb
British English
- [The term is not used as a verb.]
American English
- [The term is not used as a verb.]
adverb
British English
- [No adverbial form derived from this noun phrase.]
American English
- [No adverbial form derived from this noun phrase.]
adjective
British English
- [The term itself is a noun phrase. 'Numerical' is the adjective component.]
American English
- [The term itself is a noun phrase. 'Numerical' is the adjective component.]
Examples
By CEFR Level
- [This concept is far above A2 level.]
- [This concept is above B1 level.]
- In computer science, each object in memory has a numerical identity, its unique address.
- The detective needed to prove the numerical identity of the stolen painting with the one found in the warehouse.
- Philosophers debate whether a person's numerical identity can persist through total cellular replacement over time.
- The treaty hinges on the numerical identity of the river's source, not just its similar geographical features.
Learning
Memory Aids
Mnemonic
Think of your passport NUMBER. It doesn't describe you (that's qualitative); it picks out YOU as ONE specific person, numerically identical to the person who applied for it.
Conceptual Metaphor
IDENTITY IS UNIQUENESS (A unique number or token stands for the one and only object).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating as 'числовая идентичность' (which implies identity consisting of numbers). The correct philosophical term is 'тождество' or 'численное тождество'.
- Do not confuse with 'цифровая идентичность' (digital identity).
Common Mistakes
- Using it to mean 'having numbers that are the same' (e.g., 'The two sums have numerical identity').
- Confusing it with 'qualitative identity' (exact similarity).
Practice
Quiz
In a philosophical context, what does 'numerical identity' most precisely mean?
FAQ
Frequently Asked Questions
In practical systems, yes, a shared unique ID number is how we often operationalise or track numerical identity. Philosophically, the number is just a tool to denote the deeper concept of being one and the same entity.
Numerical identity means 'one and the same thing' (e.g., the Morning Star is the Evening Star – they are the planet Venus). Qualitative identity means 'exactly similar in properties' (e.g., two identical new coins from a mint).
Virtually never. It is a specialist term. In everyday situations, people would say 'the same thing' or 'the exact same one' instead.
Only very tangentially. 'Identity theft' concerns the fraudulent use of personal identifying information (names, numbers). 'Numerical identity' is an abstract concept about oneness, not the crime.