We live in a world of social, political, economic, and religious rupture. Ideologies polarise to fuel confrontation within communities, nations and regions of the world. At this point in the twenty-first century, humanism's focus on reason, ethics and justice offers the potential to rethink and re-engage in new ways. "What Is Humanism, and Why Does It Matter?" brings together leading humanist thinkers and activists to examine humanism and how it can work in the world. Humanism is often misunderstood. The movement includes both atheists and agnostics, who seek to make ethical sense of the world based on shared human values and a concern for human welfare, happiness and fulfillment. "What Is Humanism, and Why Does It Matter?" presents an overview and exploration of the meaning and nature of humanism, both as a philosophy and as a way of engaging with the challenges of the world.