identity of indiscernibles

E92351

metaphysical principle philosophical principle principle of identity

The identity of indiscernibles is a metaphysical principle, associated with Leibniz, stating that no two distinct entities can share all the same properties.

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All labels observed (5)

Label	Occurrences
Leibniz’s Law	3
Leibniz's law	2
Leibniz’s Law of the Indiscernibility of Identicals	1
identity of indiscernibles canonical	1
“The Identity of Indiscernibles” by Max Black	1

How this entity was disambiguated

This entity first appeared as the object of triple T775144 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.

NED1 Entity disambiguation (via context triple) gpt-5-mini-2025-08-07

Target entity: identity of indiscernibles
Context triple: [Gottfried Wilhelm Leibniz, notableIdea, identity of indiscernibles]

A. On Denoting
"On Denoting" is a seminal 1905 philosophical essay by Bertrand Russell that introduced his influential theory of descriptions and reshaped analytic philosophy of language.
B. The Logical Structure of the World
The Logical Structure of the World is Rudolf Carnap’s seminal 1928 work in which he develops a rigorous, formal reconstruction of all scientific concepts from a phenomenalist basis, serving as a foundational text of logical positivism.
C. On the Fourfold Root of the Principle of Sufficient Reason
On the Fourfold Root of the Principle of Sufficient Reason is a foundational philosophical treatise by Arthur Schopenhauer that analyzes the different ways in which the principle of sufficient reason structures human knowledge and experience.
D. Russell’s paradox
Russell’s paradox is a foundational logical contradiction in naive set theory that reveals problems with sets that contain themselves, leading to major developments in modern logic and the axiomatization of set theory.
E. Tarski's undefinability theorem
Tarski's undefinability theorem is a fundamental result in mathematical logic showing that, in sufficiently strong formal systems, the notion of truth for the language of the system cannot be defined within that same language.
F. None of above. chosen
G. Unsure - the case is ambiguous/there is not enough information to decide.

NED2 Entity disambiguation (via description) gpt-5-mini-2025-08-07

Target entity: identity of indiscernibles
Target entity description: The identity of indiscernibles is a metaphysical principle, associated with Leibniz, stating that no two distinct entities can share all the same properties.

A. On Denoting
"On Denoting" is a seminal 1905 philosophical essay by Bertrand Russell that introduced his influential theory of descriptions and reshaped analytic philosophy of language.
B. The Logical Structure of the World
The Logical Structure of the World is Rudolf Carnap’s seminal 1928 work in which he develops a rigorous, formal reconstruction of all scientific concepts from a phenomenalist basis, serving as a foundational text of logical positivism.
C. On the Fourfold Root of the Principle of Sufficient Reason
On the Fourfold Root of the Principle of Sufficient Reason is a foundational philosophical treatise by Arthur Schopenhauer that analyzes the different ways in which the principle of sufficient reason structures human knowledge and experience.
D. Russell’s paradox
Russell’s paradox is a foundational logical contradiction in naive set theory that reveals problems with sets that contain themselves, leading to major developments in modern logic and the axiomatization of set theory.
E. Tarski's undefinability theorem
Tarski's undefinability theorem is a fundamental result in mathematical logic showing that, in sufficiently strong formal systems, the notion of truth for the language of the system cannot be defined within that same language.
F. None of above. chosen

Statements (47)

Predicate	Object
instanceOf	metaphysical principle ⓘ philosophical principle ⓘ principle of identity ⓘ
alsoKnownAs	Leibniz’s Law ⓘ linked to: identity of indiscernibles principle of the identity of indiscernibles ⓘ
associatedWith	Gottfried Wilhelm Leibniz ⓘ
concerns	distinguishability of entities ⓘ identity conditions of objects ⓘ
contrastsWith	indiscernibility of identicals ⓘ
criticizedBy	Max Black ⓘ W. V. O. Quine ⓘ linked to: Willard Van Orman Quine
dependsOn	notion of property ⓘ notion of qualitative property ⓘ
field	metaphysics ⓘ philosophy of language ⓘ philosophy of logic ⓘ philosophy of physics ⓘ
hasFamousExample	Max Black’s two identical spheres thought experiment ⓘ
hasFormulation	for all x and y, if for every property P, P(x) iff P(y), then x = y ⓘ
hasInterpretation	as a contingent principle in some physical theories ⓘ as a metaphysical necessity ⓘ
hasVariant	strong identity of indiscernibles ⓘ weak identity of indiscernibles ⓘ
holdsIn	many classical metaphysical systems ⓘ
implies	if two entities share all properties, they are identical ⓘ
influenced	analytic metaphysics ⓘ philosophy of science ⓘ
logicalStatus	second-order principle ⓘ
opposedBy	haecceitism ⓘ
questionedIn	quantum mechanics ⓘ statistical mechanics ⓘ
relatedConcept	Leibnizian metaphysics ⓘ linked to: Discourse on Metaphysics haecceity ⓘ individuation ⓘ modal metaphysics ⓘ numerical identity ⓘ possible worlds ⓘ principle of sufficient reason ⓘ qualitative identity ⓘ
relatedPrinciple	law of identity ⓘ law of non-contradiction ⓘ
statedAs	no two distinct entities can share all the same properties ⓘ
status	controversial principle ⓘ
supportsView	anti-haecceitism ⓘ
timeScope	applies across possible worlds in modal formulations ⓘ
usedInArgument	arguments about individuality in quantum theory ⓘ arguments for the necessity of identity ⓘ

How these facts were elicited