Gerda Walther considered her Phänomenologie der Mystik to be her main philosophical work. Informed by her own alleged mystical experiences, this work attempts to show how spiritual beings are distinct from merely psychical beings, and that mystical lived-experiences and their objects can be distinguished from other forms of experience. Included here is a translation of the Introduction and Chapter One from the 1976 edition of Phänomenologie der Mystik, which outline her phenomenological approach to the study of mystical experience and her concept of the ego.