La promo du moment
'One citizen of your planet shall go to the capital of the Federation of Worlds. He shall live there for thirty days. If your representative can survive and demonstrate his ability to exist in a civilized society with creatures whose outward appearance and manner of thinking differ from his own, you will pass the test. You will be permitted to send your starships to other planets of the galaxy.
'If he fails the test, if prejudice, fear, intolerance or stupidity trip him up, then you world will be sealed of from the stars for ever!'
This was the ultimatum from space. The task before the world then was - who shall go? What man or woman could be found to take this frightening test for the whole of humanity and be certain not to fail?
(First published 1961)