there is no human nature, since there is no god to conceive it.
When Sartre speaks of forlornness he means that "God does not exist and that we have to face all the consequences of this." (pg.
21) The consequences of this are that life and values are stripped of their a priori meaning. With the absence of god all possibility of finding values in a heaven of ideas disappears along with him. "Nowhere is it written that we must be honest, that we must not lie ," (22) or that man must be anything besides what he wills himself to be. What strips life of it's a priori meaning and causes man to be forlorn is that everything is permissible if God does not exist because neither within him nor without does he find anything to cling to" (22). Without the existence of God man loses the ability to make excuses for himself and is condemned to the responsibility of his own
actions.
Without the existence of God man also becomes utterly responsible for his own actions. Man's anguish stems from the idea that "the man who involves himself and realizes that he in not only the person he chooses to be, but also a lawmaker, who at the same time, choosing all mankind as well as himself cannot help escape the feeling of his total and deep responsibility." (18) Man's anguish stems from his responsibility.
The essence of the utter responsibility that man must shoulder and the idea that his existence precedes his essence is expressed by the existential idea of subjectivity. By subjectivity Sartre and others mean simply that man is nothing but what he makes of himself. "Man is at the start a plan which is aware of itself nothing exists prior to this plan; there is nothing in heaven; man will be what he will have planned to be" (16). This responsibility to create oneself is only half of mans' anguish. He also suffers because in creating himself he also creates everyone else. The anguish that he experiences stems from the fact that everything that happens to man happens as if the world were watching his actions. He chooses man because his plan is the plan that he believes everyone would undertake if they were in his shoes. In this way by creating himself, man creates man and suffers because of it.