Why commas matter
Writing on fact-checking in the current number of The New Yorker, John McPhee describes a small but important point in a long article about the American shad, which he later reworked into The Founding Fish. This is the passage that poses the question:
Penn's daughter Margaret fished in the Delaware, and wrote home to a brother asking him to "buy for me a four joynted, strong fishing Rod and Real with strong good Lines …"
Anything occur to you in reading it?
This is what occurred to McPhee:
The problem was not with the rod or the real but with William Penn's offspring. Should there be commas around Margaret or no commas around Margaret? The presence of absence of commas would, in effect, say whether Penn had one daughter or more than one. The commas—there or missing there—were not just commas; they were facts. ...
Some commas are discretionary, and writers use them to suggest the pauses that occur in spoken language. Some are required to set off discrete syntactical units, such as appositives and nonrestrictive subordinate clauses, so that the reader can sail through the sentence without having to tack and return to the beginning.
Without the commas, McPhee’s reader could infer that Penn had two or more daughters, with Margaret singled out in this case. With commas, the reader could infer that Penn had one daughter, with her name supplied as additional information. (The passage appears in McPhee’s book without commas.)
McPhee leans on the fact-checkers at The New Yorker. He confesses that he writes sentences with arbitrary information, secure in the knowledge that the scrupulous fact-checking will put him right. (I’ve known newspaper reporters of this stripe.) But after The New Yorker turned down the original article and McPhee was reworking it into the book, he was on his own:
So I checked the virginal parts of the book myself, risking analogy with the attorney who defends himself and has a fool for a client. The task took me three months—trying to retrace the facts in the manuscript by as many alternate routes as I could think of, as fact-checkers routinely do.
Newspapers, sadly, lack the time and resources to do the level of fact-checking practiced at The New Yorker. The copy desk does what it can.
But what I would like the writers among you to take away from this post is a little oft-repeated homily: You are not necessarily the best judge of your own work. You need an editor to catch the things you do not notice yourself and raise the questions that you have not asked. If you are publishing solo, you are working without a net.