Quote from : Zen Mind, Beginner's Mind: Informal Talks on Zen Meditation and Practice Book

The important thing in our understanding is to have a smooth, free-thinking way of observation. We have to think and to observe things without stagnation. We should accept things as they are without difficulty. Ou mind should be soft and open enough to understand things as they are. When our thinking is soft, it is called imperturbable thinking. This kind of thinking is always stable. It is called mindfulness.