School ethics classes would be abolished at the end of the year under a bill introduced by Reverend Fred Nile, who claims their "dangerous" philosophy is linked to Nazism and communism.

Introducing his bill into the NSW upper house on Friday, the Christian Democratic Party MP said the secular humanist philosophy taught in the ethics course had led to the worst atrocities committed during World War II.

"It's relative ethics, which is the basis of secular humanism and I believe ... this is the philosophy we saw during World War II with the Nazis and with the communists," he said.

"Situation ethics, as I see it, was followed by other regimes such as the Nazis and communists."

Although his remarks provoked anger among Greens and Labor, Mr Nile continued: "Situation ethics means nothing is right and nothing is wrong ... therefore, you can kill human beings without any embarrassment and any reservations.