One of the major poets of the 20th century, T.S. Eliot considered Four Quartets to be his masterpiece. In fact, it lead him to receive the Nobel Prize for Literature in 1948. The work consists of four separate poems, each including meditations on the nature of time and its relation to the human condition. Below, an excerpt:  

Descend lower, descend only
Into the world of perpetual solitude,
World not world, but that which is not world,
Internal darkness, deprivation
And destitution of all property,
Dessication of the world of sense,
Evacuation of the world of fancy,
Inoperancy of the world of spirit;
This is the one way, and the other
Is the same, not in movement
But abstention from movement; while the world moves
In appetency, on its metalled ways
Of time past and time future.

 O dark dark dark. They all go into the dark,
The vacant interstellar spaces, the vacant into the vacant […]

And we all go with them, into the silent funeral,
Nobody’s funeral, for there is no one to bury.
I said to my soul, be still, and let the dark come upon you
Which shall be the darkness of God. As, in a theatre,
The lights are extinguished, for the scene to be changed
With a hollow rumble of wings, with a movement of darkness on darkness,
And we know that the hills and the trees, the distant panorama
And the bold imposing facade are all being rolled away-
Or as, when an underground train, in the tube, stops too long between stations
And the conversation rises and slowly fades into silence
And you see behind every face the mental emptiness deepen
Leaving only the growing terror of nothing to think about;
Or when, under ether, the mind is conscious but conscious of nothing-
I said to my soul, be still, and wait without hope
For hope would be hope for the wrong thing; wait without love,
For love would be love of the wrong thing; there is yet faith
But the faith and the love and the hope are all in the waiting.
Wait without thought, for you are not ready for thought:
So the darkness shall be the light, and the stillness the dancing.
Whisper of running streams, and winter lightning.
The wild thyme unseen and the wild strawberry,
The laughter in the garden, echoed ecstasy
Not lost, but requiring, pointing to the agony
Of death and birth.

You say I am repeating
Something I have said before. I shall say it again.
Shall I say it again? In order to arrive there,
To arrive where you are, to get from where you are not,
You must go by a way wherein there is no ecstacy.
In order to arrive at what you do not know
You must go by a way which is the way of ignorance.
In order to possess what you do not possess
You must go by the way of dispossession.
In order to arrive at what you are not
You must go through the way in which you are not.
And what you do not know is the only thing you know
And what you own is what you do not own
And where you are is where you are not.
  
Image by R. Scott Hinks, via Wikimedia Commons