Thurneysen's law
Thurneysen's law is a proposed sound law concerning the alternation of voiced and voiceless fricatives in certain affixes in Gothic. It was first posited in 1896 and published in 1898 by Rudolf Thurneysen, a comparative linguist more famous for his work on the Celtic branch of Indo-European and in particular for his . The problem. Despite being generally orthographically consistent with regard to voice, Gothic, even more so than other Germanic languages, displays a bewildering set of alternations between voiced and unvoiced spirant consonants. For example, the abstracting suffix is represented both as (, , ) and as (, ). These  alternations, and other similar patterns unexplained by Verner's law or by Proto-Germanic sound laws in general, became the subject of Thurneysen's law. The solution. Thurneysen sought to classify the alternations in a general rule as follows: Exceptions. Although seeking, in the neogrammarian tradition, to produce an exceptionless sound law Thurneysen himself acknowledged several classes of exception to his rule. Reception and criticism. The reception of Thurneysen's law has been patchy at best. Many text- and handbooks choose to completely ignore it, or to pass over it with only slight mention, and it remains among the lesser  known sound laws of Germanic philology. This is perhaps in part due to its limited scope, but certainly also due to what have been perceived as problematic aspects of its formulation, and the apparent exceptions listed above. Recent formulations. In 1968, Noam Chomsky and Morris Halle published a new and somewhat less sensitive form of Thurneysen's Law in modern notation. This version lacks Thurneysen's rules about consonantal clusters, and his observations on the effects of liquids. It has been seen, therefore, as deficient with respect to the original.