Camus uses the Greek myth of Sisyphus to develop his concerns about man's absurd condition in the universe. We need to understand the word "absurd" as "out of harmony." In Camus' thought, man is out of harmony with the world in which he lives and with himself. By exploring several philosophical theories, such as the ones posited by Heidegger, Kierkegaard, and others, he broaches the one question of philosophy that, in his opinion, matters the most.
Though not plainly asked, Camus' question points to whether man's realization of absurdity should lead to suicide. After careful discussion of various authors and a most interesting reinterpretation of the original myth, he reaches the conclusion that life should be accepted as it is. Far from despairing, man should embrace acceptance of disharmony -i.e., conflict- and make the most of his possibilities.
The central idea of the "Myth of Sisyphus" is the conflict of what Camus called the 'absurd;' the conflict occurs between what we want in the universe (enlightenment, order) and what we find in the universe (abstraction, chaos). Camus argues that just because life may have no higher purpose or calling does not mean that life is not worth living.
Camus proposes three main ways that people can adjust their thinking to accept the absurd life. They must revolt by not accepting any answers for the way the universe is, experience a greater freedom to think how they choose, and live passionate lives full of rich experiences.
Camus ends his discussion by giving the reader the mythological example of Sisyphus, who Camus feels is the perfect example of the struggle against the absurd. Sisyphus was cursed to spend all eternity rolling a rock up to the top of a mountain, only to have it roll back down before he reached the summit. Sisyphus struggles non-stop with no hope of success. Camus suggests that as long as Sisyphus accepts that there is nothing more to life than this hopeless struggle, he may find happiness in it.