These conceptions co-exist in our society, making punctuation both difficult to teach and confusing to learn. The earliest work on punctuation in English is the anonymous Treatise of Stops, Points, or Pauses, published in London in 1680. The theory of punctuation presented here is based entirely on breathing and rhetorical pauses. Modern authors are likely to attempt a compromise between the two views. I shall endeavor not to stress the former to the exclusion of the latter, but I will not knuckle under to those who apparently claim for themselves complete freedom to do what they please in the matter.
Inflexible rules governing the use of the comma are few, but there are several basic principles.
So far, so good. For the average handbook consultor, in the move from the general statement to the basic principles the Harbrace has leapt from cogent wisdom into a morass of grammatical jargon. The four principles are constructed almost entirely of complex grammatical terminology, and one gets the feeling that those who understand this terminology probably already know how to use a comma. For the reader with a little more understanding, the principles appear to contradict one another. There is nothing incorrect here, just potential confusion.