Let's say you get your assignment sheet for your next paper and skip past the bits about what the expectations are for content of the paper and what possible topics might be. You get to the important bit: required length. You might get a page count like 6 to 8 pages, confident that you'll be able to type up five full pages and an additional line the night before the paper's due. Or you'll get a word count, knowing full well that you'll be checking after every paragraph how many words you've hammered out.
I know all of this because I'm just like you. I know the thought process. A paper is made up of words, right? And the more words in a paper the better, right?
Uh, not quite.
One way folks end up writing papers is by writing in passive voice, like so:
A Clockwork Orange was written by Anthony Burgess.
You'll notice that the verb "was written" targets the subject, "A Clockwork Orange." Here's the same sentence but in active voice:
Anthony Burgess wrote A Clockwork Orange.
Notice a difference? "Anthony Burgess" is now the subject, but it isn't the target of the verb. Instead, the target is "A Clockwork Orange." The meaning of both sentences are clear, but there is a noticeable wordiness with the first sentence, the passive voice sentence, compared to the second sentence, the active voice sentence. Great for a paper right?
But it has more words! Conveys the same meaning! Yes, it does all of those things, but passive voice is unpleasant to read, especially if almost all of your paper is written in it. Sentences are bloated and unwieldy, exhausting the eyes who scan these awkwardly constructed sentences.
There are times, however, that you can use passive voice and it's a-ok, even beneficial. Passive, when used as a rhetorical weapon, can be used to focus the sentence on a particular object in the sentence. A common phrase executed by Illinois politicians goes a little something like this:
"Mistakes were made."
Who made the mistakes? We don't know, and Mr. Politician-Man is not about to admit it to us either. Were he to structure it like, "They made mistakes," he's clearly tossing the blame at someone else. But saying, "Mistakes were made," places the blame on some bodiless, nameless entity.