Difference (philosophy)

Difference is a key

Difference in Leibniz's law

Kant's critique

In his Critique of Pure Reason, Immanuel Kant argues that it is necessary to distinguish between the thing in itself and its appearance. Even if two objects have completely the same properties, if they are at two different places at the same time, they are numerically different:

Identity and Difference.— ... Thus, in the case of two drops of water, we may make complete abstraction of all internal difference (quality and quantity), and, the fact that they are intuited at the same time in different places, is sufficient to justify us in holding them to be numerically different. Leibnitz [sic] regarded phaenomena as things in themselves, consequently as intelligibilia, that is, objects of pure understanding ..., and in this case his principle of the indiscernible (principium identatis indiscernibilium) is not to be impugned. But, as phaenomena are objects of sensibility, and, as the understanding, in respect of them, must be employed empirically and not purely or transcendentally, plurality and numerical difference are given by space itself as the condition of external phaenomena. For one part of space, although it may be perfectly similar and equal to another part, is still without it, and for this reason alone is different from the latter .... It follows that this must hold good of all things that are in the different parts of space at the same time, however similar and equal one may be to another.^[1]

Difference in structuralism

Structural linguistics, and subsequently structuralism proper, are founded on the idea that meaning can only be produced differentially in signifying systems (such as language). This concept first came to prominence in the structuralist writings of Swiss linguist Ferdinand de Saussure and was developed for the analysis of social and mental structures by French anthropologist Claude Lévi-Strauss. The former was concerned to question the prevailing view of meaning "inhering" in words, or the idea that language is a nomenclature bearing a one-to-one correspondence to the real. Instead, Saussure argues that meaning arises through differentiation of one sign from another, or even of one phoneme from another:

In language there are only differences. Even more important: a difference generally implies positive terms between which the difference is set up; but in language there are only differences without positive terms. Whether we take the signified or the signifier, language has neither ideas nor sounds that existed before the linguistic system, but only conceptual and phonic differences that have issued from the system. The idea or phonic substance that a sign contains is of less importance than the other signs that surround it. ... A linguistic system is a series of differences of sound combined with a series of differences of ideas; but the pairing of a certain number of acoustical signs with as many cuts made from the mass thought engenders a system of values.^[2]

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