Men do not sufficiently realize that their future is in their own hands. Theirs is the task of determining first of all whether they want to go on living or not. Theirs the responsibility, then, for deciding if they want merely to live, or intend to make just the extra effort required for fulfilling, even on their refractory planet, the essential function of the universe, which is a machine for the making of gods (la fonction essentielle de l'universe, qui est une machine à faire des dieux).

Concluding sentences ; often just the last part of the last sentence is quoted, in the form: "The universe is a machine for making gods." - The Two Sources of Morality and Religion (1932)