This introduction to Meister Eckhart is the result of decades of research on Meister Eckhart, starting with an interdisciplinary doctor dissertation about contemplative and active Life in Eckhart's German sermons (1968, revised 2018). The author translated a compendium of Eckhart's sermons in modern German (1979, last edition 2022) and he published a lot of contributions on Eckhart's spiritual teaching with special interest on ethical implications: virtues, social behavior and Human dignity. This book will inform about Eckhart's practical metaphysics: (1) in his general teaching on creation, God's timeless working, the relation between God and Human by processes of knowledge, grace, justice and liberty; (2) in his thinking on unity in wording, intellectual knowledge and using images which correct themselves; (3) in his combining of revelation in his biblical commentaries with abstraction, wisdom and life-learning, (4) in his teaching of becoming the "son" of God by the birth of God in the human soul, (5) in the important interconfessional and interreligious implications of the mystical immediacy in his teaching, (6) in defending Eckhart against some dogmatic objections concerning his vernacular teaching.