perfectibility is at hand

I came across this gem of a quote while I was doing some research for my forthcoming John Steinbeck blog:

"We have usurped many of the powers we once ascribed to God.

"Fearful and unprepared, we have assumed lordship over the life or death of the whole world - of all living things.

"The danger and the glory and the choice rest finally in man. The test of his perfectibility is at hand.

"Having taken Godlike power, we must seek in ourselves for the responsibility and the wisdom we once prayed some deity might have."

Given by John Steinbeck upon receiving the Nobel Prize in Literature in 1962 (emphasis added). Full text here.