Note 159 — VIII Language as a Historical Product: Phonetic Law
Reading edition
Footnote 159: In practice phonetic laws have their exceptions, but more intensive study almost invariably shows that these exceptions are more apparent than real. They are generally due to the disturbing influence of morphological groupings or to special psychological reasons which inhibit the normal progress of the phonetic drift. It is remarkable with how few exceptions one need operate in linguistic history, aside from “analogical leveling” (morphological replacement).