Can someone paraphrase this quote from Elie Wiesel and then explain what it means?

"To be indifferent - for whatever reason - is to deny not only the validity of existence, but also its beauty. Betray, and you are a man; torture your neighbor, you're still a man. Evil is human, weakness is human; indifference is not."

Humanity is capable of both beauty and evil. Indifference is an absence of emotion and thus a lack of humanity.

Explanation:

There are many that say the opposite of love is not hate, it is indifference. To love is to care. To hate is to care. To be indifferent is to not care. What the paragraph is saying is that humans are emotional. Negative emotions such as hate and negative actions such as betrayal and and torture are human just as much as love and caring are. Robots are indifferent. They are no more capable of evil than they are of good.

Eli is explaining how his humanity was stripped away when all individuality was denied to them in the concentration camps. It means if you are the same as everyone else, you are no longer human, since individuality is a human characteristic, it seperates us from animals. Without individuality you are not human.