What is the path of inquiry for understanding the nature of the mind?

That which rises as ‘I’ in this body is the mind. If one inquires as to where in the body the thought ‘I’ rises first, one would discover that it rises in the heart.

That is the place of the mind’s origin. Even if one thinks constantly ‘I-I’, one will be led to that place. Of all the thoughts that arise in the mind, the ‘I’ -thought is the first. It is only after the rise of this that the other thoughts arise. It is after the appearance of the first personal pronoun that the second and third personal pronouns appear; without the first personal pronoun there will not be the second and third.

How will the mind becomer quiescent?