Commas and Coordinating Conjunctions Before Dependent Clauses

Question

"For what do we live, but to make sport for our neighbors, and laugh at them in our turn?" -- Jane Austen

Many famous authors and writers use coordinating conjunctions and commas in this way. Are these commas used to make it easier to parse, or are they indicating a pause, or are they indicating a tonal shift? What are the specific guidelines for commas preceding a coordinating conjunction that is between an independent clause and subsequent dependent clauses?

In the example sentence, I understand why there is a comma between "neighbors" and "and": the coordinating element contrasts the inversion of the dependent clauses. I, however, do not understand the comma between "live" and "but." "For what do we live" is an independent clause, not an introductory clause.

Here is another example from a college writing center's website.

"When connecting two independent clauses with a comma and a word like 'however' or 'therefore,' you can either divide the sentence into two sentences, or use a semicolon, which can be used to connect two independent clauses without a coordinating conjunction."

So, what do you think?

Answer 1

Jane Austen may be an admirable model for many things in English prose, but modern punctuation is not one of them:

In the 19th century and earlier (when rules were generally more lax than they are today), comma use was pretty much a crapshoot. That is, writers rolled one in when they felt like it, which was usually when a natural pause seemed to occur. So in the first line of “Pride and Prejudice” (1813), Jane Austen wrote:

“It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife.”

By about a century later, comma rules had been codified such that both commas in the sentence (after “acknowledged” and “fortune”) would be dispensed with. — Ben Yagoda, “Fanfare for the Comma Man,” New York Times website, 9 April 2012.

This codification in the early 20th century is chiefly due to the efforts of two brothers, Henry Watson Fowler and Francis George Fowler, whose 1906 book The King’s English advocated for a radical reduction in comma usage, mostly on semantic grounds.

The first punctuation guides, George Puttenham’s The Arte of English Poesie (1589) and Simon Daines’ Orthoepia Anglicana (1640), treated any written text as a script to be read aloud, which, of course, was quite practical for poetry and drama. A comma indicated a short pause, a semicolon a longer one, and a colon longer still. One could term this comma usage elocutionary or prosodic.

That punctuation should be syntactical was a novelty introduced by Ben Jonson’s The English Grammar in 1640. Until the Fowler brothers, there was a chaotic mixture of both prosodic and semantic comma placement.

It was common throughout the 19th century to bracket any relative clause, whether essential or non-essential, with commas, as in the line from Pride and Prejudice Yagoda cites. Modern practice is both syntactic and prosodic, as English speakers usually take a breath or pause before a non-essential clause, but the commas also mark the semantic distinction between the two types of clauses. The same rule applies to appositives, where breathing pauses have nothing to do with where commas go.

In your example from the same novel, the two commas are strictly prosodic and by modern rules, completely unnecessary.