The world should have known about--and believed--the atrocities Hitler was committing against the Jews and others because there were witnesses who were telling the world about them. Unfortunately, the world did not believe. The same is true of the Jews themselves. They had warnings, in the form of witnesses, who tried to tell them what was going to happen and was already happening. Because no one wanted to believe such horrible things could be true, no one listened.
Three specific and significant examples of such witnesses can be found in Night, by Elie Wiesel, though there are many others, as well.
The first witness is Moshe the Beadle, Elie's friend and religious mentor. Of course Moshe is a bit of an eccentric character, but when he is deported as a foreign Jew and comes back with the stories of what is happening to the Jews, no one quite believes him. Because he is kind of a crazy uncle-type, a rather mystical spiritualist, and of course because of the Jews' unwillingness to believe such things could happen, Moshe's warnings go unheard.
The second witness who goes unheeded is Madame Schachter. In fairness to the Jews who heard but did not heed her, the woman's warnings come in the form of a crazy rant which does not make any sense to them--until they arrive at the death camp. She knows what is possible, however, because her husband and two sons have already been taken away. The Jews should have listened to her warning, though there is little they could have done at this point to avoid what was ahead of them.
She screams and rants ceaselessly about fire and smoke, but her words do not make sense to those around her, and eventually they abuse her into silence. In her case, the Jews did not make the connection between her ravings about fire and the atrocities Moshe the Beadle told them about, but Madame Schachter serves as a witness to them, nevertheless.
The most obvious witness is Elie himself. Though he wrote this story from the distance and perspective of time, his voice serves as a witness to man's cruel and senseless inhumanities. He says,
“For the dead and the living, we must bear witness.”
The most compelling commitment Elie makes to being a witness is recorded on his first night in the concentration camp:
Never shall I forget that night, the first night in camp, which has turned my life into one long night, seven times cursed and seven times sealed....Never shall I forget those moments which murdered my God and my soul and turned my dreams to dust. Never shall I forget these things, even if I am condemned to live as long as God Himself. Never.
Not only will Elie never forget, but he will continue to tell this story as a witness to what can happen, testifying to what is possible in the dark depravity of man's souls.
This theme of witnesses who try to warn others is consistent with similar themes in the story, such as missed opportunities to avoid worse trouble. It is clear that Elie Wiesel highlights characters in his story who testify about the horrors to come as well as uses his own voice to testify about what else might happen if man's worst nature is left unwatched and unchecked.