The active voice isn’t always the best choice.
“Mistakes were made.” “Prepaid fees will be placed in trust.” “It is suggested that the null hypothesis can be rejected.”
The passive voice has long been dismissed as a hallmark of turgid prose. “Many a tame sentence,” wrote Strunk and White in The Elements of Style, “can be made lively and emphatic by substituting a transitive in the active voice for some such perfunctory expression as there is, or could be heard.” George Orwell, in “Politics and the English Language,” agreed: among the “tricks by means of which the work of prose construction is habitually dodged” is that “the passive voice is wherever possible used in preference to the active.”
But did you notice something about these advisories? They use the passive to bad-mouth the passive. This hypocrisy reminds us that prohibition is bad policy. No construction could have survived for millennia if it did not serve a purpose.
The passive is a voice: a means of expressing who did what to whom. In the active voice, the doer is the subject: Squirrels ate my birdseed. In the passive, the done-to is the subject—My birdseed was eaten—and the doer is an oblique object (… by squirrels) or omitted altogether. The verb changes to a participle (eat becomes eaten), which must be introduced by a form of be or get, or lurk in a subordinate clause (Stung by the review, he never wrote again).
Why does English need the passive? Think of a grammar as an app for converting a cluster of ideas into a string of words. English relies mainly on word order to do this: Dog bites man is different from Man bites dog. Inconveniently, though, the grammatical ordering of words to convey a meaning may diverge from the optimal flow of ideas in the reader’s mind. A sentence’s first words should link back to the preceding discussion, fixing the reader’s attention on a familiar entity, and preparing her to learn something new about it. Sometimes, the natural flow of ideas aligns with the grammatical order dictated by who bit whom. Other times, these demands clash.
To resolve this conflict, some languages use case markers to signal nouns’ roles, allowing writers to scramble word order. English’s workaround is the passive, another way of fiddling with word order while holding the event constant.
The passive is the voice of choice, then, when the done-to is in the spotlight. In recounting the climax of Oedipus Rex, in which a messenger explains the backstory, it is more natural to say The messenger had been given a baby to get rid of by a shepherd from the Laius household than A shepherd from the Laius household had given the messenger a baby to get rid of. All eyes are on the messenger, so the sentence should begin with him.
Also, the passive’s ability to hide the doer, though abused by mistake-makers, is handy when the doer’s identity is irrelevant. In the news item The suspect was arrested in connection with the killing of three Israelis, we don’t need to know that a guy named Shlomo made the arrest.
Then why is the passive so common in soggy prose? Good writing narrates a story, advanced by protagonists who make things happen. Inept writers work backward from their own knowledge, plonking down ideas as they think of them. So they begin with the outcome, and throw in the cause as an afterthought. The passive makes that all too easy.
Yes, bad writers overuse the passive. But the passive is not just something that is overused by bad writers.