Systematization and the origin of rules

One of the design features of language is its systematicity: to a considerable extent, the rules of grammar relate not to the world outside, but only to other rules. They exist in autonomy from external motivations. Subject-verb inversion in the Germanic languages as a marker of interrogatives is a well-known example of such an externally unmotivated rule. The notion of systematization implies a process whereby such rules have evolved from pre-systematic externally motivated origins.

In this particular case: Greenberg’s constituent order universal #11 proposed that only those languages with sentence-initial interrogative words will ever allow subject-verb inversion in questions. There is, however, an obvious functional basis for fronting question words: Jespersen’s principle of actuality. Moreover, of the languages which front question words, many demarcate focussed from presupposed material by a focus-marking flag. In other languages, it may be that the verb itself may function as such a flag, that is, subject-verb inversion may be the functional analog of a demarcative focus marker. The best evidence for the functional unity of focus marking and subject-verb inversion is their complementary distribution, sometimes within the same language. The genuine systematicity of subject-verb inversion may then be the outcome of functional external motivations, and a series of analogical steps.

More generally, it may be that other aspects of the autonomization or emancipation of language can be explained by reference to processes that are attested in observed language change. Analogy leads to systematization (and possibly even to recursiveness), as ritualization leads to displacement, and its linguistic aspects (sound change and grammaticalization) lead to arbitrariness, discreteness, and double articulation.