I went to Communism as one ...

I went to Communism as one goes to a spring of fresh water, and I left Communism as one clambers out of a poisoned river strewn with the wreckage of flooded cities and the corpses of the drowned.
 Arthur Koestler

Quotes from the same author

To sell oneself for thirty pieces of silver is an honest transaction; but to sell oneself to one s own conscience is to abandon mankind.
 Arthur Koestler
Nothing is more sad than the death of an illusion.
 Arthur Koestler
In my youth I regarded the universe as an open book, printed in the language of equations, whereas now it appears to me as a text written in invisible ink, of which in our rare moments of grace we are able to decipher a small segment.
 Arthur Koestler
I am not sure whether ethical absolutes exist. But I am sure that we have to act as if they existed or civilization perishes.
 Arthur Koestler
Einstein's space is no closer to reality than Van Gogh's sky . The glory of science is not in a truth more absolute than the truth of Bach or Tolstoy, but in the act of creation itself. The scientist's discoveries impose his own order on chaos, as the composer or painter imposes his; an order that always refers to limited aspects of reality, and is based on the observer's frame of reference, which differs from period to period as a Rembrant nude differs from a nude by Manet.
 Arthur Koestler