The passive voice is a very versatile construction. It is particularly useful when the performer of the action is unknown or irrelevant to the matter at hand. Thus a police report might say A car was broken into last night on Laurel Road when the perpetrator is unknown. You might write in a memo Office mail is now delivered twice a day where what is important is the frequency of mail delivery, not the identity of the people working in the mailroom.
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You can also use the passive voice to conceal the performer of an action or the identity of a person responsible for a mistake: We had hoped to report on this problem but the data was inadvertently deleted from our files. Who deleted the data? By using the passive voice the writer is able to avoid identifying the guilty party. This virtue of obscuring responsibility is in part what makes the passive voice so tempting to anyone working in an organization where something has gone wrong. Since the occasions for avoiding responsibility are multitudinous, passive verbs are bound to thrive for at least the foreseeable future.
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Surprisingly enough, you can also use the passive voice to emphasize the performer of the action by putting the performer in a prepositional phrase using by at the end of the sentence: The breakthrough was achieved by Burlingame and Evans, two researchers in the university’s genetic engineering lab. In this way the passive voice functions like a well-run awards ceremony. It creates suspense by delaying the announcement of the names.
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Another virtue of passive constructions is that they allow you to emphasize a modifying adverb, as many politicians know well: My remarks have been grossly distorted in the press.
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Scientists ordinarily use the passive voice to describe natural processes or phenomena under study. Here is a passage from an essay by the psychiatrist Paul R. McHugh, where he emphasizes real psychological processes in refuting the notion that children ordinarily suppress memories of trauma:
… severe traumas are not blocked out by children but remembered all too well. They are amplified in consciousness, remaining like grief to be reborn and reemphasized on anniversaries and in settings that can simulate the environments where they occurred.
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In technical and scientific articles, especially in the presentation of experimental methods, researchers use the passive voice as a conventional means of impersonal reporting. The passive voice allows them to avoid calling attention to themselves and to omit reference to any subjective thoughts or biases they might have brought to their work. The effect is to lend the article the air of objectivity. Here is a typical example from a paper in molecular biology:
The protein concentration required to saturate the solid phase was determined and the amount of bound protein was quantified by the micro-bicinchoninic acid protein assay.
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The experiment seems to run itself.
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On some occasions you will want to use the passive voice to preserve the coherence of your writing. Suppose you are discussing a certain topic—immigrant labor in Europe, for example—from the point of view of an economist. Your subject then is how the various economies treat workers who come from other countries and are not citizens. Here is how one economist, John Kenneth Galbraith, discusses this subject:
In the last forty years, in Germany, France, and Switzerland, and in lesser measure, Austria and Scandinavia, the provision of outside workers for the task for which indigenous laborers are no longer available has been both accepted and highly organized. The factories of the erstwhile German Federal Republic are manned, and a broad range of other work is performed, by Turks and Yugoslavs. Those in France are similarly supplied by what amounts to a new invasion of the Moors—the vast influx from the former North African colonies.
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In this passage there is not a single active verb. Galbraith thus violates one of the most common commandments of writing handbooks: “use active verbs.” But would the passage be clearer or easier to read if Galbraith had made the workers the subject of the sentences?
… Turks and Yugoslavs man the factories of the erstwhile German Federal Republic and perform a broad range of other work. What amounts to a new invasion of the Moors—the vast influx from the former North African colonies—supplies those in France.
For Galbraith’s purpose—describing the economy rather than the social groups in European society—the passive voice works fine. In fact, using the active voice might seem oddly inappropriate and, hence, distracting to the reader.
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The passive voice can also help you make smooth transitions. Here is a passage in which the astronomer Robert P. Kirschner discusses what happens to an aging star.
… In some [very old] stars, carbon-rich matter from the core is dredged up by convection. The freshly synthesized matter then escapes, forming a sooty cocoon of graphite. Eventually fuel runs out, and the inner core of the red giant congeals into a white dwarf.
A white dwarf is protected from total gravitational collapse not by the kinetic pressure of gases; the carbon and oxygen in its interior are in an almost crystalline state. The star is held up by the quantum repulsion of its free electrons.
Let’s see how the same passage would read if the second paragraph were written with active verbs:
… Eventually the fuel runs out, and the inner core of the red giant congeals into a white dwarf.
It is not the kinetic pressure of gases that protects a white dwarf from total gravitational collapse; the carbon and oxygen in its interior are in an almost crystalline state. The quantum repulsion of its free electrons holds the star up.
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The subject of discussion—the white dwarf—now seems secondary. The chemical and physical processes inside the star take precedence. As a result, the essay, rather than the star, is in danger of collapsing.
