FMA writes (from zip code 02138):
My roommate [MS] told me Christopher Hitchens is a wonderful prose stylist. I was skeptical, so I opened Hitch 22 at random. The first sentence reads:
"My mother having decided that Tonbridge was out of the question for her sensitive Christopher, some swift work had to be done to reposition me in the struggle—the whole aim and object of the five years at Mount House—to make me into a proper public-school boy [sic]."
I have put in bold the part of the sentence that bothers me. Essentially, there is a fragment next to a sentence; there is no predicate for "my mother." I noted that Mr. Hitchens is also missing a comma after "mother," but my roommate believes that's just the thing that would make the sentence wrong. According to him, "My mother having decided that Tonbridge was out of the question for her sensitive Christopher," is a modifier of "some swift work," so he believes there is no problem with the sentence. He also believes there is no problem sentences like
"My mother being very old, I walked in quietly [sic]."
Will you tell the world he's wrong? I tried to come up with analogous examples, but he thinks there's something about the present perfect tense that makes these constructions unique. He claims authority because he is a native English speaker—I, while not a native speaker, do claim native competence.
In this case, I'm afraid, I have to tell the world that FMA is wrong, and his roommate and Christopher Hitchens are right. Hitchens is using a construction discussed on pages 1265-6 of CGEL, where the followed two examples are given:
His hands gripping the door, he let out a volley of curses.
This done, she walked off without another word.
CGEL explains that
The underlined non-finites are supplements with the main clause as anchor. [The examples shown] contain a subject, and belong to what is known as the absolute construction, one which is subordinate in form but with no syntactic link to the main clause. [...]
In [none of these examples] is there any explicit indication of the semantic relation between the supplement and the anchor. This has to be inferred from the content of the clauses and/or the context.
Absolute constructions are quite common in formal varieties of English, especially in styles influenced by exposure to Latin. Latin writers were especially fond of ablative absolutes, about which Allen and Greenough write
The ablative absolute is an adverbial modifier of the predicate. It is, however, not grammatically dependent on any word in the Sentence: hence its name absolute (absolitus, i.e. free or unconnected).
Confining our attention to maternal absolutes, it's easy to find 19th-century examples:
Wilkie Collins, The Woman in White: Her mother having told me as little about the child as she told me of herself, I was left to discover (which I did on the first day when we tried her at lessons) that the poor little thing's intellect is not developed as it ought to be at her age.
Benjamin Disraeli, Coningsby: Lord and Lady Gaverstock were also there, who never said an unkind thing of anybody; her ladyship was pure as snow; but her mother having been divorced, she ever fancied she was paying a kind of homage to her parent by visiting those who might be some day in the same predicament.
Charles Dickens, Little Dorrit: Mr. Flintwinch taking kindly to the idea of getting rid of him, and his mother being indifferent, beyond considerations of saving, to most domestic arrangements that were not bounded by the walls of her own chamber, he easily carried this point without new offence.
Charles Dickens, Oliver Twist: Your mother being dead, I knew that you alone could solve the mystery if anybody could, and as when I had last heard of you you were on your own estate in the West Indies—whither, as you well know, you retired upon your mother's death to escape the consequences of vicious courses here—I made the voyage.
George Eliot, Daniel Deronda: But Gwendolen, nevertheless, continued to receive polite attentions from the family at Quetcham, not merely because invitations have larger grounds than those of personal liking, but because the trying little scene at the piano had awakened a kindly solicitude towards her in the gentle mind of Miss Arrowpoint, who managed all the invitations and visits, her mother being otherwise occupied.
There are several common idioms of this form, such as "all things being equal" (originally perhaps a translation of the Latin ablative absolute ceteris paribus) and "all things considered".
Here at Ware College House where I'm the resident Faculty Master, we generally have first-year roommates start the semester by drafting and signing an agreement about how they'll share their space and how they'll settle disputes. I don't believe that I've ever seen a roommate contract that specified methods for the arbitration of syntactic disagreements, but in case this sort of thing comes up again, Language Log is here to help.