In the first scholarly exposition of Maria Montessori’s moral philosophy, Patrick R. Frierson presents an empirically-grounded ethics that takes its start from our tendency to strive for excellence and emphasizes mutual respect, social solidarity, and love. Laying out a compelling, Montessorian approach to ethical life, Frierson constructs an account of human agency based on children, who when attentively at work on self-chosen tasks, have agency worthy of respect. Through this interpretation of children’s agency, he introduces the core concept of Montessorian “character”: in...