A 2014 Daily Mail article by Simon Heffer, "The Pedant’s Revolt", contains an interesting assortment of peeves about language (mostly about the meanings of words). I was familar with some of them, but I found the first incredibly surprising, and I've been wondering whether it represents a preexisting prescriptive position or is something that Heffer came up with himself.
ABLE Only living beings are able. To say that ‘this key may be able to open the door’ is wrong. A man may be able to open the door using the key, or the key may unlock the door.
This certainly doesn't seem to describe any real fact about the English language. The Oxford English Dictionary (OED) says the word able comes from a French or Anglo-Norman word of various spellings and various meanings, including some that apply to inanimate objects:
(of a person) able-bodied, muscular, powerful (second half of the 12th cent. in Anglo-Norman), (of an inanimate object or fact) suitable, fit, appropriate (second half of the 13th cent.), (of a person) competent, expert (end of the 13th cent.), legally capable, entitled, or qualified (end of the 13th cent. or earlier in Anglo-Norman, frequently with reference to ability to inherit; this use is apparently not paralleled in continental French until later (1390 with reference to ability to sue, 1461 with reference to ability to inherit)), (of a ship) seaworthy (c1440 or earlier in Anglo-Norman), (of a person) intelligent, clever (1555)
Part b. of the OED definition of the English word says
Since very late Middle English or early modern English, to be able (to) has been used (with all tenses of to be) as an alternative to or replacement for can and could (see can v.1 II.) in contexts relating to ability and possibility, and is now chiefly so used. In standard English since that period can has lacked an infinitive, present participle, past participle, and gerund; to be able (to) is used to replace this verb in compounds with other auxiliaries (especially supplying a future tense and perfect tenses) and in non-finite constructions.
The OED entry provides the following example from 1551 of "be able" being used with the subject "any Lawe":
1551 T. Wilson Rule of Reason sig. Eiv Neither can any Lawe be able violentlye to force the inward thought of man.
Regardless, peeves about the meanings of words are often not based on actual usage, so it seems quite possible that somebody came up with this "rule" before Heffer. Does anyone know of an earlier example of somebody insisting that the word able can only refer to "living beings"?