Mathematical Structures of Early Indo-European Numeral Systems
In honor of Joseph H. Greenberg
Carol F. Justus

Indo-European (IE) language grammars have been organized in terms of inflectional and derivational categories. Such categories often reflect the system that Latin grammarians, building on their Greek forebears, established. Greenberg's work in defining categories of language on the basis of the extent to which human languages vary offers a way to capture systematic differences in terms of universal categories of language.

Interests of Greenberg, the anthropologist, however, also extended to linguistic systems that encoded cultural systems as when he (1978) pointed out that the names of number words may change because a language has adopted a new numeral base. Such an understanding presupposes that mathematical functions are encoded in the linguistics of a numeral system. Such mathematical functions underlying a "pure" numeral system are that of numeral base and exponentiation on that base (Greenberg 2000:373-374). So exponential bases of the decimal system, besides 10 (one times the base) include 100 (10 the power of one), 1000 (10 to the power of three), and so on, powers that result from the mathematical principle, exponentiation.

Since Szemerényi (1960), the Proto-Indo-European (PIE) numeral system has generally been thought to have been a decimal system. This is based primarily on Szemerényi's phonological analysis of the decades, the multiples of 10 before 100 (Greenberg's 'augends'). Among other problems (Justus 1996:66-77), the reconstruction of a decimal system for PIE does not account for the Germanic long hundred of 120, a number which is neither a power of 10 nor of 12 (Justus 1999:138-140). It is not a "pure" numeral system nor does it belong to a "mixed base" category (e.g., French quatre vingt 'four-20(s)' or '80': Greenberg 2000:774). Earlier studies have related it to a duodecimal or sexagesimal system, systems which Greenberg (2000:773) says remain unexplained.

Following Greenberg's anthropological concerns, one turns to the cultural context of early counting. Studies of the Sumerian sexagesimal system have shown that it was not based on 60 but on alternating multiples of 10 and 6 (Damerow & Englund 1989; Damerow 1996). Such early systems differed from modern numeral systems in that they lacked a base and with it the function, exponentiation. Justus (1999:145) termed alternating units of multiplication such as 10 and 6 'collection units', while Luján (1999) termed them 'improper bases'. Both terms reflect their pre-exponential, non-base status.

Greenberg (1978) established that changes in the linguistics of numeral systems reflected changes in a base. This study argues that the change from pre-exponential to exponential system built on a base also affects the linguistic form for expression of numerals. It further illustrates how the form of data within specific linguistic domains is related to variation in the human cultural systems that they encode.


Sources Cited:

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