Student: Roshi, you said not to stop thinking, but to be free from thinking, and I wonder if you could explain what it means to be free from thinking?
Suzuki Roshi: What I meant was don’t be bound by your thinking. When you reach a conclusion by thinking, you will have some definite idea. Actually, that is why you think: to have a definite answer. But that is not possible.
Student: So what should you do?
Suzuki Roshi: You can think, and thinking will help you, of course. But you should know, at the same time, that that answer will not be definite. So you think, but you are free from thinking. That is what I meant: to have what we call a double edged blade. So double-edge think: don’t think and think. It works two ways. This is the double nature, the double construction of Buddhist philosophy: thinking construction and non thinking construction. (from the Suzuki Roshi archives)
I think this exchange illuminates Dogen’s “think of not thinking” from the Fukanzazengi – which he borrowed from Yakusan.