What do we mean by saying that existence precedes essence? We mean that man first of all exists, encounters himself, surges up in the world-and defines himself afterwards. If man as the existentialist see him is not definable, it is because to begin with he is nothing. He will not be anything until later, and then he will be what he makes of himself. Thus, there is no human nature, because there is no God to have a conception of himself. Man simply is.