The subject of Phonetic Law and Analogy belongs to Psychology as well as to Philology; it originated, however, and was for a long time kept within the domain of the latter discipline. When it first came into the foreground of our interest, it was agitated by scholars in historical philology. The experience of daily linguistic research suggested both the question and the answer, and in fact the main importance of the whole problem was seen in the influence which its solution must have upon the methods of detailed investigation.