When you are a survivor, you know what death is and there is no need of any explanation but you have to learn what life is. And this constitutes a paradox for many people. The problem is concrete and Primo Levi is a proof that we need to be more human with survivors to avoid their suicide. Keep in mind that survivor is still a victim even if he is alive. Avoid this error of interpretation because for him this is crucial. By the way, the perpetrators of a genocide use this fact to deny its existence. The protection of the survivor is also the protection of the testimony. So imagine that the survivor is already the human legacy of a genocide and Mankind has to defend him against the attack of oblivion because society will urge to forget him. Now you know the need of a survivor. Do your duty.