Krista Tippett speaks with Canadian philosopher and Catholic social innovator Jean Vanier. He founded the L'Arche movement, over 130 communities in 34 countries centered around people with mental disabilities. To many, Jean Vanier is simply one of the wise men in our world today. He has spent his life practically exploring the most basic, paradoxical teachings of Christianity-notions about power in humility, strength in weakness, and light in the darkness of human existence.