This study builds on a small, under-acknowledged body of educational works that speak to the problem of an overly technical focus on teaching, which negates a more authentic consideration of what it means to teach, including an exploration of the spiritual and moral dimensions. A need for educational change and the teacher's authentic way of being are presented as the basis for the primary research question: "What does it mean to be an authentic teacher?" The study consists of two equally intensive parts, i.e., a theoretical and empirical investigation. The theoretical developed a framework on authenticity, drawing from the Buddhist and Christian theological traditions; the Twentieth Century philosophical writings of Buber and Heidegger; and the in-depth review of conceptual and empirical educational literature. This framework supported the empirical design, which was a phenomenological study of six teachers in a small Catholic urban K-8 school. An empirical framework on authenticity evolved through the data analysis. Ultimately, the theoretical and empirical parts were integrated into a comprehensive framework on teacher authenticity, defined as follows: "Teacher authenticity is a trust that, through the desire and intention to care, the teacher can awaken through teaching a profound life-giving potential for the well-being of oneself, others, and the world. This trust is the teacher's faith perspective, and is lived, dynamic, and iterative, which makes authenticity an ongoing process". A sub-question was also presented in the study: "What does it mean for the researcher to engage as an authentic learner in the research process?" The focus on the researcher as an authentic learner presented an expanded view of reflexivity, probing deeply into the philosophical, psychological, and spiritual dimensions of the researcher's learning process throughout the study. The implications of the study are presented, focusing on the professions of teaching and research, and also showing the relevance for education and society. The most impending implication pertains equally to teachers and to researchers, and emphasizes the need for professional development programs of self-learning and self-formation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]