What makes solitude a positive experience? What distinguishes experiences of solitude from experiences of loneliness? We review some of the literature on the benefits of solitude, focusing on freedom, creativity, and spirituality. Then, we argue that the relationship between agent and environment is an important factor in determining the quality of experiences of solitude. In particular, we find that solitude may support a person’s sense of agency, expanding the possibilities for action that a person has, and creating the conditions for authenticity. We describe a phenomenology of solitude, based on a study that explores the nature of experiences of loneliness and solitude in a religious community. One finding is that solitude is characterised by presence, whereas loneliness is characterised by absence. Another finding is that solitude can contribute to a sense of empowerment that enables agents to pursue and achieve the goals they find valuable.