H: Boggarts are shape-shifters. They take the shape of whatever a person fears the most. That's what makes them so terrifying.
　　L: Yes. Luckily, a very simple charm exists to repel a boggart. Let's practice it now. Without wands, please. After me. Ridikulus!
　　S: Ridikulus!
　　L: You see, the incantation alone is not enough. What really finishes a boggart is laughter. You need to force it to assume a shape you find truly amusing. Let me explain.

重点讲解

　　祛除（repel）幻形怪的魔咒（charm）是Ridikulus，这个词是ridiculous（荒谬的）的变形体。换句话说，作者要告诉我们就是，祛除心底的恐惧，最好的方法就是蔑视它，认为它不值一提。

　　当然，只有咒语（incantation）是不够的，还要有个药引子，那就是——笑声。在心中给恐惧想个好笑的（amusing）形状。电影中的一个情节就是，一个害怕斯内普教授的学生，看着幻形怪变成的思内普教授，想象他穿着老奶奶的衣服，结果想象变成了事实，全班同学都逗笑了。

　　想起裴多菲的一句话“绝望之为虚妄，正与希望相同”——异曲同工之妙。