There is a strange prejudice that I have encountered a number of times in the editorial world, namely the belief that one cannot use the word “as” in a causative sense, to mean “because.” Multiple people have tried to tell me that “as” has only a temporal significance and cannot be used in any other way. I’m really not sure whence this belief originates, for it is simply false, and I suspect the majority of English speakers would recognize it as such. This usage is certainly quite frequent in the spoken language. No one would bat an eye at phrases such as “As I am not tall enough, I cannot get on the ride” or “I’m going to break out of prison, as the institution has little to offer me.”
As evidence for the acceptability of this usage, one can cite Strunk and White’s The Elements of Style. Here’s what it has to say regarding this usage of “as”: “Two part sentences of which the second member is introduced by as (in the sense of ‘because’), for, or, nor, or while (in the sense of ‘at the same time’) likewise require a comma before the conjunction.” Not only do Strunk and White—who are hardly known for their leniency—endorse the use of “as” in this sense, they do not even believe it unusual enough to provide an explanation or justification. They simply take it for granted that the word can be used in this way.
It is not merely Strunk and White who accept this usage, moreover: Merriam-Webster has an article on just this subject. While the article notes that many commentators advise against the use of “as” in a causal sense because of its potential for ambiguity, it points out that usage is over 1,000 years old and generally causes no problems: “And yet our research shows that, in real life, conjunctive uses of as are rarely confusing since the conjunctive as rarely appears in a sentence that is contextless, and the context can often help disambiguate the meaning of as.”
The article concludes by declaring “as” in this sense a bit risky and formal but quite acceptable.
I must say that part of what I find appealing about “as” rather than “because” or “since” is precisely its formality, the sense that while it’s meaning may be the same as other, less ambiguous, options, it exists in a higher register. And the use of the appropriate register provides diversity and ornamentation to good writing. Too often, I find that many grammarians and grammar police are so interested in enforcing rules and bashing out any form of ambiguity from the language that what we are left with is a written brutalism, a sparse and uninteresting set of options that might (might!) be lucid, but lack any kind of nuance aesthetic charm. I think most of us would prefer that the language remain open, full of options to be played with, sounds to be explored, and even ambiguities that leave open wider horizons of semantic possibility. Indeed, it has often been remarked that one of the qualities of poetry contributing to its depth is precisely its ambiguity. Of course, “as” in a causal sense hardly constitutes poetry, but I believe the general principle to be the same.