Salman Rushdie begins "On Censorship" with an extended metaphor. He talks about how we don't think much about air because it is "all around us, plentiful, freely available, and broadly breathable." It might not be perfect, but it isn't something we have to worry about. It's just present; it's not a subject for discussion.

But then Rushdie asks us to imagine giant faucets up in the sky, faucets that spew air. Then he tells us to think about what it would be like if someone gradually turned off those faucets. It might not seem like a big deal at first, but pretty soon, we would notice that our supply of air was getting thinner and thinner. We could still breathe mostly freely, but the atmosphere would be changing. Then, if the faucets were turned off too much, we might start to protest majorly as it became harder and harder to breathe.

Rushdie is using this extended metaphor to help us think about liberty. We generally don't think much about out liberty. Rather, we tend to take it for granted. Our freedom might not be perfect, but it is usually there for us in a measure that doesn't require a lot of discussion. However, when censorship appears, it is like someone is turning off the faucet of our liberty, Rushdie implies. And the more censorship there is, the more we begin to notice the lack of freedom in the creative arts.