I suppose I could refer to style lists for each client when I'm writing, but that would break the flow and seems a waste of time that could better be spent creating value for the client. Instead, I go by what feels right and my memory -- often imperfect -- of the client's preferred usages. I rely on our excellent proofreader, a retired English teacher who has style notes for each client and eyes like a hawk, quick to pounce on the slightest error. It's an imperfect system, but it works pretty well.
But there is no proofreader other than myself when I am blogging. And I certainly never refer to a standard style manual. Again, it would break the flow and waste time -- and what would it add, really? The result, however, is that my blog is covered with a residue of inconsistency, thick as dust. Sometimes I italicize the titles of books. Sometimes I put quotes around them. There is no consistency in my use of serial commas. My usages of that and which lean toward the loosey-goosey. Basically, I try for something that sounds reasonably conversational, makes sense to the reader, and looks OK on the page. The determination, however, is whimsical and changes over time. Is this bad? Should I feel guilty about this "anything goes as long as it feels good" laxity? Sometimes I do, and sometimes I don't.
But I'll probably spend less time obsessing about it since reading Arnold Zwicky's post titled "Foolish Hobgoblins" in Language Log. (H/t to TNH's Particles at Making Light.) When Emerson penned "A foolish consistency is the hobgoblin of little minds," he didn't define "foolish." Zwicky gives us an idea of where he stands by compressing the phrase and transposing the adjective. His post is devoted to the proposition that individual whim trumps hair-splitting rules when it comes to variable usages.
As a linguist, I have to point out that inconsistency is just another name for variability, and variability is not some pesky defect of languages, but a central feature of them (along with, at least, opposition, compositionality, redundancy, ambiguity, synonymy/paraphrase, and hierarchical structure -- plus, of course, shared norms). Language (both spoken and written) varies from person to person, from social group to social group, from occasion to occasion, and even for a single person on a single occasion, from moment to moment. And this is a very good thing. It would be insane to try to enforce a single choice between variants, on all occasions, for everyone.It's a fascinating meditation on variability in language and why it's a good thing, filled with interesting and amusing examples -- including this reference to the impulsive, do-your-own-thing side of Justice Antonin Scalia.
So the question is: when is regulation (in favor of consistency) appropriate, and when should variability flourish? This is far too big a question for me to answer here, but I will talk about some cases -- mostly from the mechanics of written English -- where it seems to me a case can be made for letting people do whatever they feel like doing at the moment. You could always choose one variant, or always choose another (in either case recognizing that other people make different choices, and that's ok), or choose between them in some systematic way, or choose between them at your whim (in which case there might be a system in some of your choices, but not one that you're aware of -- and some of your choices will be made at random).
Now, a few words on apostrophes. Mark Liberman has already explored this territory, in a posting that takes up Jonathan Starble's considering (in the Legal Times)It's curious how some people equate word choices with moral choices, especially since, although Zwicky doesn't mention it, a case could be made -- and probably has been made -- that Gödel's incompleteness theorems formally undermined the whole idea of consistency in language usage more than 70 years ago. For any set of rules in a given tradition of usage, there will always be some usage that is impossible to resolve within that set of rules.the deep divide that exists among the nation's intellectual elite regarding one of society's most troubling issues -- namely, whether the possessive form of a singular noun ending with the letter s requires an additional s after the apostrophe.and goes on to examine the practice of Justice Antonin Scalia in this regard, which is variable (Kansas's, Ramos's, witness's; but Stevens', Adams', Tibbs'), and his own, concluding, puckishly:On this question, I agree with Associate Justice Scalia. At least, I'm rarely certain what the spelling should be in such cases, and so I add s or not, as the spirit moves me. If this is the thin edge of the moral-relativist wedge, so be it -- Antonin and I stand together, behind the right to follow the dictates of conscience in each individual s+possessive circumstance.I'm astonished that Mark was not besieged by people screaming THERE OUGHT TO BE A RULE. Mark is, after all, advocating punctuation by whim: "as the spirit moves me". He even throws out a mischievous reference to "the thin edge of the moral-relativist wedge", alluding to the many people who believe that making linguistic choices is a moral issue, so that tolerating (or, worse, advocating) variability is moral relativism of the most deplorable sort.
In the end, we're all thrown back on our own resources, our own temperament and our own common sense. Sort of like navigating life's winding road -- you wouldn't want to spend so much time reading the map that you lose sight of the road.