In many types of academic writing (with scientific writing as perhaps the most obvious example) passive voice is expected; it is also seen as a marker of formality and of objectivity, as it removes the personal subject.

But, as explained in Give your opinions, in the humanities it is conventional to express personal opinion and to incorporate subjective responses into academic argument. So, although you may think that using the passive voice adds a note of seriousness to your writing, or even that you might be expected to produce writing of this kind, it is better at all times to avoid the passive where possible.  



Not only is the second example above shorter (and therefore more concise in a literal sense), but it is also simpler and a more dynamic form of expressing ideas.