A sound change can progress hesitantly from one similar environment to the next, for example, by joining forces with another sound change […]. (p. 56)
- Schuchardt (1972)

If I were obliged to include the notion of "unexceptionability" in my credo, I would relate it to the occurrence of sporadic sound change, rather than to sound laws, in the sense that every sound change in some phase is sporadic. (pp. 62-63)
- Schuchardt (1972)

Even in the realm of mechanical sound change – to make use of neogrammarian terminology – I find things that are quite different from mere, self-contained processes of sound change that can be wrapped up in rigid formulas. I see here the lively endless interplay of innumerable impulses in the midst of which individual items stand out in more vivid outline. (p. 57)
- Schuchardt (1972)

[…] a sound change often extends over a broad area, i.e. in a series of contiguous dialects. Did it develop spontaneously in each of these? No. Rather, as we can trace historically in many cases, it spread out from one point in the form of radiation. Why should a sound change have developed spontaneously in each of the idiolects that comprise a dialect? […] Even Delbrück says, "that changes in pronunciation begin with the individual and spread from there to a greater and greater number of speakers through imitation". (p. 49)
- Schuchardt (1972)

Fashionable sound change, that is to say, more or less conscious or, even better, voluntary sound change frequently has attendant innovations. The sound change can suffer false application. It can even be increased by one degree. It can produce parallel sound changes. If, in the end, as can be attested historically, any particular peculiarity of pronunciation of a really style-setting personality, a prince, a courtier, an actor is copied voluntarily in his own circle, or if a teacher imposes his own pronunciation upon his pupils, it cannot be disputed that the impulse for sound change is one of personal choice. Individual sound change can without further ado be attributed to personal choice. (p. 51)
- Schuchardt (1972)

In regard to the manner in which a sound change is transmitted from individual to individual, from community to community, there seems to be a great divergence of opinion. I confess that in all this I do not see by any means the exclusive play of unconscious activity […] I shall not go far astray if I consider the unexceptionability of the sound laws as incompatible with the share that consciousness, in my opinion, has in sound change. (p. 50)
- Schuchardt (1972)

There is always talk about the principle of least effort whenever the causes of sound change are being debated. What is more natural than making things easier whenever overfrequency provides the strongest impulse for this and wherever the danger of misunderstanding is least? (p. 59)
- Schuchardt (1972)