If you have a white wall, that's when we did Zen meditation, it's easier if you're just facing a wall.

如果家中有面空墙，我们可以进行坐禅，面对空墙会相对容易。

普林斯顿公开课 - 人性课程节选

If you have a white wall, that's when we did Zen meditation, it's easier if you're just facing a wall.

如果家中有面空墙，我们可以进行坐禅，面对空墙会相对容易。

普林斯顿公开课 - 人性课程节选