The desire to hold on to a pattern, the tendency to “correct” a disturbance by an elaborate chain of supplementary changes, often spread over centuries or even millennia—­these psychic undercurrents of language are exceedingly difficult to understand in terms of individual psychology, though there can be no denial of their historical reality.  What is the primary cause of the unsettling of a phonetic pattern and what is the cumulative force that selects these or those particular variations of the individual on which to float the pattern readjustments we hardly know.  Many linguistic students have made the fatal error of thinking of sound change as a quasi-physiological instead of as a strictly psychological phenomenon, or they have tried to dispose of the problem by bandying such catchwords as “the tendency to increased ease of articulation” or “the cumulative result of faulty perception” (on the part of children, say, in learning to speak).  These easy explanations will not do.  “Ease of articulation” may enter in as a factor, but it is a rather subjective concept at best.  Indians find hopelessly difficult sounds and sound combinations that are simple to us; one language encourages a phonetic drift that another does everything to fight.  “Faulty perception” does not explain that impressive drift in speech sounds which I have insisted upon.  It is much better to admit that we do not yet understand the primary cause or causes of the slow drift in phonetics, though we can frequently point to contributing factors.  It is likely that we shall not advance seriously until we study the intuitional bases of speech.  How can we understand the nature of the drift that frays and reforms phonetic patterns when we have never thought of studying sound patterning as such and the “weights” and psychic relations of the single elements (the individual sounds) in these patterns?

Every linguist knows that phonetic change is frequently followed by morphological rearrangements, but he is apt to assume that morphology exercises little or no influence on the course of phonetic history.  I am inclined to believe that our present tendency to isolate phonetics and grammar as mutually irrelevant linguistic provinces is unfortunate.  There are likely to be fundamental relations between them and their respective histories that we do not yet fully grasp.  After all, if speech sounds exist merely because they are the symbolic carriers of significant concepts and groupings of concepts, why may not a strong drift or a permanent feature in the conceptual sphere exercise a furthering or retarding influence on the phonetic drift?  I believe that such influences may be demonstrated and that they deserve far more careful study than they have received.