"Generally speaking, our mind is predominantly directed towards external objects. Our attention follows after the sense experiences. It remains at a predominantly sensory and conceptual level. In other words, normally our awareness is directed towards physical sensory experiences and mental concepts. But in this exercise, what you should do is to withdraw your mind inward; don't let it chase after or pay attention to sensory objects. At the same time, don't allow it to be so totally withdrawn that there is a kind of dullness or lack of mindfulness. You should maintain a very full state of alertness and mindfulness, and then try to see the natural state of your consciousness—a state in which your consciousness is not afflicted by thoughts of the past, the things that have happened, your memories and remembrances; nor is it afflicted by thoughts of the future, like your future plans, anticipations, fears, and hopes. But rather, try to remain in a natural and neutral state."This is a bit like a river that is flowing quite strongly, in which you cannot see the riverbed very clearly. If, however, there was some way you could stop the flow in both directions, from where the water is coming and to where thewater is flowing, then you could keep the water still. That would allow you to see the base of the river quite clearly. Similarly, when you are able to stop your mind from chasing sensory objects and thinking about the past and future and so on, and when you can free your mind from being totally 'blanked out' as well, then you will begin to see underneath this turbulence of the thought processes. There is an underlying stillness, an underlying clarity of the mind. You should try to observe or experience this ...

— Dalai Lama

from The Art of Happiness