Anyhow, last week as I was thumbing through the assigned Strunk and White reading, I came across the entry for "flammable" in the chapter on misused words and expressions. I'm quoting it since I think it's one of the more memorable passages:
An oddity, chiefly useful in saving lives. The common word meaning "combustible" is inflammable. But some people are thrown off by the in- and think inflammable means "not combustible." For this reason, trucks carrying gasoline or explosives are now marked FLAMMABLE. Unless you are operating such a truck and hence are concerned with the safety of children and illiterates, use inflammable (47)
I read this three times last week. The first time, I laughed because I was insulted by the last sentence. The second time, I paused and thought, "Ooookay, I need a snack to up my blood sugar. I'm probably reading this wrong." The third time was just as brilliant; I thought, "Huh. Interesting. Note to self: blog about this later."
It's an interesting entry. When I searched Merriam-Webster Online, I got some interesting results. "Flammable" means capable of being set on fire while the entry for "inflammable" is more itneresting. The entry lists two definitions: "flammable" and "easily excited or angered." The etymology of "flammable" and "inflammable" is identical--they come from the Latin inflammare. The entries include that "inflammable" was first used in 1605; "flammable" was first used in 1813. There's 213-year gap between their usage, they mean the same thing in standard usage but Merriam-Webster never explains why.
And so, this is why Strunk and White is pretty awesome. The AP Stylebook doesn't even have entries for "flammable" and "inflammable."
But then, there's a problem: Do we then default to Merriam-Webster, which says that the two are interchangeable? Would you use "inflammable" when you need a synonym for "flammable" or vice versa? That could confuse readers. Or should you use "flammable" since your story will be read by people who don't know the distinction between the two words and have been using "inflammable" as the antonym for "flammable" for most of their lives? Do you submit to the awesomeness of Strunk and White and use "inflammable"?
My brain got tired sorting this all out. It's just one word that I may or may not use during my entire existence as an individual that writes. The world just might not end. For now, I opt for being consistent and taking the matter up with copyeditors and editors in the distant future.