Explain how sartre might defend existentialism against the claim that it leaves a moral vacuum

The claim that existentialism leaves a moral vacuum is a common one against this philosophy, and one that Sartre was aware of. Existentialism places freedom at the centre of human experience, and this includes the freedom from traditional moral views, which at first glance, could be worrisome for some people.

However, getting rid of moral traditions imposed by society is a choice: the choice to define your own morality. And by defining this morality, you replace old values with new ones. Therefore, there is no vacuum as there is no "empty space." When some social rules are removed from our ethical code, some other personal rules replace them. Sartre places great value on "authenticity." This is the creation of our own self in freedom. Through authenticity and freedom, we design ourselves, both as individuals and in society. Existentialism, therefore, does not imply the loss of ethics (and therefore, the lack of morals), but only the creation of a new ethics based on individual freedom and authenticity.

cassius, casca, and their allies plant false documents to manipulate brutus to join their cause to remove caesar. after doing so, they visit brutus at night in his home to persuade him of their views. there they plan caesar's death. brutus is troubled but refuses to confide in his devoted wife, portia. on 15 march, caesar's wife, calpurnia, urges him not to go to the senate. she has had visionary dreams and fears the portents of the overnight storms.

as for symbolic actions, the narrator's tearing down the wallpaper in an attempt to find the "woman" in the wallpaper represents her struggle to retain or regain her sanity.   the wallpaper has been part of her confinement and by her tearing it down, she is freeing herself from that confinement.