This paper lays out the moral theory of philosopher and educator Maria Montessori (1870–1952). Based on a moral epistemology wherein moral concepts are grounded in a well-cultivated moral sense, Montessori develops a threefold account of moral life. She starts with an account of character as an ideal of individual self-perfection through concentrated attention on effortful work. She shows how respect for others grows from and supplements individual character, and she further develops a notion of social solidarity that goes beyond cooperation toward shared agency. Partly because she attends to children's ethical lives, Montessori highlights how character, respect, and solidarity all appear first as prereflective, embodied orientations of agency. Full moral virtue takes up prereflective orientations reflectively and extends them through moral concepts. Overall, Montessori's ethic improves on features similar to some in Nietzschean, Kantian, Hegelian, or Aristotelian ethical theories while situating these within a developmental and perfectionist ethics.