This is the first edition of Physiology and Therapeutics, a new translation of four lectures given in Dornach, October 7-9, 1920, appearing in German as Physiologisch-Therapeutisches auf Grundlage der Geisteswissenschaft in the volume of the same title, Bibliographie-Nr. 314, published by the Rudolf Steiner Nachlassverwaltung, Dornach, Switzerland, 1975. The translation is from the most recent German edition and is by Alice Wulsin and Gerald Karnow.