English

Noun

indiscernibility of identicals

1. (philosophy) The principle that if two objects are absolutely identical then they must be indistinguishable from one another with respect to all of their properties.
   • 1943, Willard V. Quine, "Notes on Existence and Necessity," The Journal of Philosophy, vol. 40, no. 5, p. 113:

     One of the fundamental principles governing identity is that of substitutivity—or, as it might well be called, that of indiscernibility of identicals. It provides that, given a true statement of identity, one of its two terms may be substituted for the other in any true statement and the result will be true.

   • 2004, Peter Alward, "The Spoken Work," The Journal of Aesthetics and Art Criticism, vol. 62, no. 4, p. 335:

     For example, Levinson claims that a Stamitz symphony containing a "Manheim rocket"—a novel device in Stamitz's day—is an exciting musical work, but a work written today with the same sound structure would be funny rather than exciting. Since the Stamitz symphony and the (hypothetical) contemporary sound-identical work differ in properties, it follows from the indiscernibility of identicals that they are distinct musical works.

Synonyms

• principle of substitutivity

See also

• identity of indiscernibles