Dostoyevsky once wrote “If God did not exist, everything would be permitted”; and that, for existentialism, is the starting point. Everything is indeed permitted if God does not exist, and man is in consequence forlorn, for he cannot find anything to depend upon either within or outside himself.
Sartre thought, despite his use of the word ‘forlorn’ here, that total freedom – freedom from any kind of constraint or expectation was a good thing, it was the point at which modern man had arrived now he was free of any misapprehension about the existence of God.
Yet with no boundaries, as he hints, there is nothing to depend upon. If i am free I may do precisely as I wish, but if everyone else is free too, there is nothing to stop the man in the street spitting in my face or, worse, shooting me. I cannot have any expectation of the conduct of my fellow men.
Sartre yearned for a society in which men acted freely, according only to their impulses, but society proves that you very quickly have to have laws and codes of behaviour to which people are held against their freedom.
Those laws and social attitudes can be invented by the crowd, by Sartre and his adherents, or by an all-seeing, all-knowing, utterly just being.
Which would you prefer?