Active voice has become the preferred mode of communication in scientific and legal writing. It has been shown to provide clearer explanations with less confusion. However, the preference for passive voice, which began in the 19th century, was actually based on the idea that the passive voice represented objectivity. A fact or conclusion is emphasized in passive voice rather than the creator or actor which makes that conclusion seem less personal and more objective. In light of this, the modern preference for removing passive voice might reflect cultural changes as well as good grammar. Today, individuality not objectivity is the hallmark of our culture, and as a consequence, active voice sounds better to us.
Did you understand the preceding paragraph? Did it seem overly wordy or convoluted? Perhaps it struck you as formal or too formal? It was written in the passive voice. Here is a translation to the active voice.
Professionals in the legal and scientific arenas have declared a strong preference for active voice. Because it is clearer and less prone to confusion, lawyers and scientists have adopted active voice. However, lawyers and scientists beginning as early as the 19th century preferred passive voice because it represented objectivity. By using the passive voice, writers emphasize the fact over the creator or actor which makes the fact seem less personal and more objective. In light of this, perhaps modern writers choose the active voice as much for cultural as grammatical reasons. Today, we are more concerned with individuality than objectivity, and so we prefer active voice.
Just as Professor Strunk pointed out in his famous book The Elements of Style, the second paragraph written in active voice is more direct, vigorous, and slightly more concise. These are ideal characteristics for scientific and legal writing that demand precision. Did you, though, notice that it was less objective and more specific?
In the general cry for efficient and effective communication, it is taken for granted that the passive voice should be rooted out at every turn, but even Strunk pointed out that passive voice is both necessary and convenient in many writing situations. It is often a matter of emphasis which determines the voice to be used. Here is an example.
Passive: Cholesterol has been determined by scientists to contribute to heart disease.
Active: Scientists have determined that cholesterol contributes to heart disease.
In the first case, cholesterol is the star and draws the attention whereas scientists are the stars of the second sentence. They are both relatively concise and comprehensible, but they are subtly and importantly different in emphasis. Writers do need the seemingly outdated passive voice and should object to its removal from their toolboxes just as Picasso would object to blue being removed from his palette. Admittedly though, a writer should use active voice when the primary goal is to convey accurate information.
Here are a couple of links that make the case for active voice in legal writing and demonstrate the zeal for active voice in scientific writing.