Every Philosopher had a way to achieve the deepest of the concentration level. There are various ways to bring is balance between the subconscious and conscious so to reunite them.
To sum up all the practices Breathing is the way.
Do you think you are breathing?
Breathing the essence of life itself, from birth to death, it is the breath that is needed by the body for its performance or you are declared dead.
Our body in existence must have been the deepest philosophy of the Greatest Philosopher. Trillions of unit of work in fraction of seconds , without any noise but silence. What it requires is the magic of cosmos.
We Breath in oxygen and Breath out carbon dioxide every one is familiar with it, but the one thing that science has still not observed in the mixture of gases is Prana. Sometimes in separate conditions also people feel like they can't breath something like a near death experience though enough of oxygen may be present, this brings the philosophy of Prana into realm.
Its better to be silent when you read than to think of the things you are not doing now