Hildegard Peplau’s work formally began the development, basis and revolution of nursing knowledge for general nursing as well as for psychiatric mental health nursing. Her underlying philosophical assumptions and interpersonal relations theory not only emphasized the science of nursing that was empirically rooted and dominant from the time, but she illustrated how nursing as an art could equally contribute to the nursing knowledge, practice, and research that is so evident in nursing today. As a pioneer of nursing, Peplau helped to bridge the gap between theory and practice that continues to build on nursing’s knowledge base today. On the Canadian front, nurse leader, Cheryl Forchuk, continues to put it to the test.