You will ask, why is it that 15 years after Liberation, there are still many people who are moderates, and even some who are still rightists? (Audience laughter). It’s because thought work (思想工作) is just this difficult, it needs a period of time, and we can’t force them to wash their brains (不能强迫他们洗脑筋). (Audience laughter). We can only encourage them, we can only persuade them[.] (Mao 1964).