Everything is permissible if God does not exist, and man is consequently abandoned, for he cannot find anything to rely on – neither within nor without.
What do we mean here by “existence precedes essence”? We mean that man first exists: he materializes in the world, encounters himself, and only afterward defines himself.
Choosing to be this or that is to affirm at the same time the value of what we choose, because we can never choose evil. We always choose the good, and nothing can he good for any of us unless it is good for all.