The important thing for each of us about any book is not whether it is wicked in itself but whether it can be safely read by _me_ at this particular moment.
– C.S. Lewis to Mary Neylan, 26 April 1941; cited in _Yours, Jack: Spiritual Direction from C.S. Lewis_ (HarperOne, 2008), 83.
Here, Lewis focuses quite rightly not on some theoretical or abstract standard for judging a book–or, we could say, a television show, a radio broadcast, a play, an Internet message board, or even a conversation with others. He does not think there much value in worrying over assigning a book to “good” or “bad” categories in the sense of “righteous” or “wicked” in and of itself.
Rather, he quite rightly focuses on its fruits and outcome for each individual. To be sure, there are some works whose effect can hardly help but be irredeemably evil, and some which could rarely work wrong. But there is a broad middle ground where most things dwell.
We are apt to want rules to judge by–What rating does this movie have?–and so forth. But Lewis reminds us that this essentially abandons the necessity of moral judgment. A person troubled by lust might find that some works simply aren’t in his best interest, while another might not notice those elements at all. A person prone to melancholy or self-pity might need to avoid certain tear-jerkers not because they are evil, but because of the broader ripple effect on her mood and actions later.
We can, if inclined, use this as an excuse or self-justification: we can “handle” the rough stuff. The principle, though, ought to make us more discriminating, more discerning, and more attuned to the fruits of what we consume.
As Lewis remarked elsewhere, Christians should not avoid bars and the like because they are too good for such places. They avoid them because they know they are not good enough.