This quote is from the end of ‘Adventure of Ideas’ and edited by Cobb:

Peace is primarily a trust in the efficacy of Beauty.  This trust in self-justification of Beauty introduces faith, where reason fails to reveal the details.  And this trust finally comes as a gift.  The gift of trust comes largely beyond the control of purpose.  The comes through the vision of something which stands beyond, behind, and within the passing flux of immediate things; something which is real, and yet waiting to be realized; something which is a remote possibility, and yet the greatest of present facts; something that gives meaning to all that passes, and yet eludes apprehension; something who possession is the final good, and yet is beyond all reach; something which is the ultimate ideal, and the hopeless quest.