Xavier Le Pichon, one of the world's leading geophysicists, helped create the field of plate tectonics. A devout Catholic and spiritual thinker, he raised his family in intentional communities centered around people with mental disabilities. He shares his rare perspective on the meaning of humanity — a perspective equally informed by his scientific and personal encounters with fragility as a fundament of vital, evolving systems. Le Pichon has come to think of caring attention to weakness as an essential quality that allowed humanity to evolve.