That seems to support the quote, actually: “it” typically has a single antecedent, or a small enough set that the correct antecedent can be easily identified by context. When it cannot be identified by context, this is seen as a writing error (such as here, here, or here).
That seems to support the quote, actually: “it” typically has a single antecedent, or a small enough set that the correct antecedent can be easily identified by context. When it cannot be identified by context, this is seen as a writing error (such as here, here, or here).
Possible counterexamples (there are probably better ones):
“It’s the economy, stupid”
http://sub.garrytan.com/its-not-the-morphine-its-the-size-of-the-cage-rat-park-experiment-upturns-conventional-wisdom-about-addiction (http://lesswrong.com/r/discussion/lw/ing/open_thread_september_1622_2013/9rdu)
http://parenting.blogs.nytimes.com/2013/08/25/its-not-a-problem-its-called-being-a-child/
For each of those, the meaning of “it” is clear from context. If it weren’t, then it would be uncommunicative writing.
All of these are dummy subjects. English does not allow a null anaphor in subject position; there are other languages that do. (“There”, in that last clause, was also a dummy pronoun.)