It is unnecessary to believe in the supernatural source of evil. Only people can do all the bad things. -Joseph Conrad

Joseph Conrad (Polish-born English writer): It is unnecessary to attribute the root of evil to supernatural factors. Humans are enough to commit all kinds of evil deeds.

Try not to. To do or not to do. -Yoda

Master Yoda (the protagonist in Star Wars): Don't try. To do or not to do.