Elie Wiesel was a Nobel Peace Prize winner, Holocaust survivor and author -- but he is perhaps best known for giving a voice to the voiceless. He died Saturday at 87.

After surviving the Auschwitz concentration camp after being sent there when he was 15 years old, Wiesel spoke out in a time when most Holocaust survivors remained silent.

He wrote his first book, Night, in 1960. It would be translated into 30 languages and read by millions.

Wiesel wrote more than 60 books, won a Nobel Peace Prize in 1986 and received more than 100 honorary degrees in his lifetime.

To remember his passion for activism and peace, here are 10 of Wiesel’s most powerful quotes:

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On speaking out.

I swore never to be silent whenever and wherever human beings endure suffering and humiliation. We must always take sides.

On indifference.

The opposite of love is not hate, it's indifference. The opposite of beauty is not ugliness, it's indifference. The opposite of faith is not heresy, it's indifference. And the opposite of life is not death, but indifference between life and death.

On racism.

No human race is superior; no religious faith is inferior. All collective judgments are wrong. Only racists make them.

On friendship.

Friendship marks a life even more deeply than love. Love risks degenerating into obsession, friendship is never anything but sharing.

On forgetting.

To forget the victims means to kill them a second time. So I couldn't prevent the first death. I surely must be capable of saving them from a second death.

On borders.

When human lives are endangered, when human dignity is in jeopardy, national borders and sensitivities become irrelevant.

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On activism.

There is much to be done, there is much that can be done.

On time.

We know that every moment is a moment of grace, every hour an offering; not to share them would mean to betray them. Our lives no longer belong to us alone; they belong to all those who need us desperately.

On human rights.

Human rights are being violated on every continent. More people are oppressed than free. How can one not be sensitive to their plight? Human suffering anywhere concerns men and women everywhere.

On freedom.