identity of indiscernibles

E92351

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

Observed surface forms (1)

Surface form Occurrences
Leibniz’s Law 1

Statements (47)

Predicate Object
instanceOf metaphysical principle
philosophical principle
principle of identity
alsoKnownAs identity of indiscernibles
surface form: Leibniz’s Law

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
Willard Van Orman Quine
surface form: W. V. O. 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 Discourse on Metaphysics
surface form: Leibnizian 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

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

identity of indiscernibles alsoKnownAs identity of indiscernibles
this entity surface form: Leibniz’s Law
Gottfried Wilhelm Leibniz notableIdea identity of indiscernibles