I was struck the other day by how often that injunction is wrong. Take the previous sentence: I could have written, It struck me the other day, but that’s hardly more informative and it describes the experience less accurately than the passive construction. That It stands for A certain idea, but the idea didn’t experience anything. I did -- so I ought to be the subject of the sentence.
The passive voice allows for some slippery sentences, because the subject is no longer the same as the person performing the action. John Wilkes Booth shot Lincoln is active. Lincoln was shot by John Wilkes Booth is passive. Nothing so wrong with it yet, but a passive sentence allows you to delete the by clause, so you can get Lincoln was shot, with no information about who pulled the trigger. The guilty party has disappeared from the sentence and the theater.
That’s one reason people advise writers to avoid the passive voice. There’s also a rhythmic advantage to rapid-fire active sentences, in back-and-forth action for example . Here’s William Blake from 1793:
I asked a thief to steal me a peach: / He turned up his eyes.
I asked a lithe lady to lay her down: / Holy and meek she cries.
So far, nice and crisp: the narrator asks one thing from each of them, and the thief and lady do another. But look what happens next:
As soon as I went /An angel came:
He wink’d at the thief, /And smil’d at the dame;
And without one word spoke / Had a peach from the tree,
And between earnest and joke / Enjoy’d the lady.
There are no by classes in the last stanza, but what happened? The angel was given a peach by the thief and a warm reception by the lady. Yet the thief has disappeared behind the tree, and the lady has been relegated to the direct object of the sentence.
Why does this work so well? Because indirection is the point of the poem. The narrator asks directly and gets no satisfaction, but the angel merely winks and smiles and gets everything he desires. How often do we find ourselves writing about situations in which we’re not sure which direction to take or who’s responsible? To share an experience of uncertainty, the passive comes in handy.