摩訶止觀 2.48

2.48

First, explaining the four movements: the mental consciousness is formless and cannot be seen, but is distinguished according to four marks: not-yet-thinking, about-to-think, thinking, and having-thought. Not-yet-thinking means the mind has not yet arisen; about-to-think means the mind is on the verge of arising; thinking means directly fixing on an object and abiding; having-thought means the conditioning of the object has ceased. If one can thoroughly comprehend these four, one enters the single mark of marklessness.