The Philosophical Ethics in Early Childhood project aims to advance knowledge of preschool children’s ethical understanding and explores the effectiveness of philosophical discussion of children’s literature and extension activities for fostering ethical development in early childhood. In this article we discuss results of our ethics education study with preschool children, including pre-post measurement of experimental and control groups and a 12-week educational intervention focusing on the themes of fairness, empathy, personal welfare and inclusion versus exclusion of peers. As compared to (...) our control group, study results demonstrated significant developments in our experimental group’s ability to respond to ethical questions, increased use of emotion markers, and increased use of justification terms in support of responses. (shrink)