Camus often refers metaphorically to the feeling of absurdity as a place of exile. Once we have acknowledged the validity of the perspective of a world without values, of a life without meaning, there is no turning back. We cannot simply forget or ignore this perspective. The absurd is a shadow cast over everything we do. And even if we choose to live as if life has a meaning, as if there are reasons for doing things, the absurd will linger in the back of our minds as a nagging doubt that perhaps there is no point.
It is generally supposed that this place of exile—the absurd—is uninhabitable. If there is no reason for doing anything, how can we ever do anything? The two main ways of escaping the feeling of absurdity are suicide and hope. Suicide concludes that if life is meaningless then it is not worth living. Hope denies that life is meaningless by means of blind faith.
Camus is interested in finding a third alternative. Can we acknowledge that life is meaningless without committing suicide? Do we have to at least hope that life has a meaning in order to live? Can we have values if we acknowledge that values are meaningless? Essentially, Camus is asking if the second of the two worldviews sketched above is livable.