NORMAL - Holocaust survivor and Nobel laureate Elie Wiesel told thousands of people Tuesday at Illinois State University that indifference is the worst sin of all. "The opposite of love is not hate, but indifference," said the 80-year-old author. | Video

The opposite of education is not ignorance, beauty is not ugliness, and life is not death. The true opposite in each case is indifference, he added.

"Indifference not only hurts the victim, but also the person who becomes indifferent," he added.

Humanity shouldn't be defined by a person's relationship with God, but rather by how a person treats others, Wiesel said during an hour lecture that was filled with traditional stories, life memories and philosophical reflections.

The author most famous for his tiny tome "Night," which recounted the horrors of life inside Auschwitz and other Nazi death camps, gave two talks Tuesday at ISU, both drawing overflow crowds.

Braden Auditorium's 3,500 seats quickly filled for the 7 p.m. lecture, and ISU workers had to turn hundreds of people away. Many listened through speakers set up in the halls.

Wiesel finished the evening with a book signing.

Born in land that was part of Hungary during the war and now is in Romania, a young Wiesel spent time in Auschwitz, Buchenwald and other death camps.

His father, mother and younger sister died, joining an estimated 6 million Jews who perished under the Third Reich. Eventually, Wiesel landed in a French orphanage and later was reunited with his older sisters.

As an adult, he became one of the best-known witnesses to the Holocaust as a writer and professor.

In his evening lecture, he said an ISU student asked him earlier that day if world religions are to blame for the wars of the 20th and 21st centuries. Wiesel said he believes religion isn't the problem, fanaticism is.

A fanatic shows unjustified pride and violence and believes only he has the ear of God, all the answers, and the only key to heaven's gate.

"He believes God should be his prisoner," Wiesel said.

Two weeks ago, Wiesel led a protest in New York, calling for the United Nations to not welcome Iranian President Mahmoud Ahmadinejad, but rather indict him for inciting crimes against humanity.

"If I see a trend, it is my duty to pull the alarm," Wiesel said of the incident. Ahmadinejad, whose country has worked toward building nuclear weapons, denies the Holocaust happened and has said he wants to destroy Israel.

"I have learned from my life one must take such words seriously," said Wiesel, alluding to Adolf Hitler and the world's indifference to his fanatic hatred of Jews.

"I've learned the enemies of my people are the enemies of all people. Someone who hates a minority hates all minorities.

"But they (Nazi leaders) believed they were the agents of civilization," said Wiesel.

People can't sit idly by, thinking they have the right to be indifferent, he said.

"The world is in danger," said Wiesel, and people looking at civilization need to ask "Where are we?"