Retired Professor in Religious Studies at the University of South Africa and now Research Associate in the Faculty of Theology and Religion at the University of Pretoria, J.S. Krüger writes that his book does not depend on any single academic discipline nor is it based in a particular religious tradition. According to the author,
This investigation listens to the wise and enlightened of the past and the present in all cultures, religions and mystical traditions; the visionaries and explorers of the inner world. The days of monocultural, monoreligious isolation are numbered – our time is crying out for a new, inclusive-pluralistic, totalistic vision, appropriate to the cultural conditions of today and the foreseeable tomorrow, beyond the mere rehashing of traditional views and dogmas. The various wisdom traditions are not to be mingled, but respected in their individual integrity. I also assume some continuity among the various mystical traditions evolved by humanity, and among the great mystics who are conspicuous among that differentiated but continuous stream.
Krüger, J.S. Signposts to Silence. Metaphysical Mysticism: Theoretical Map and Historical Pilgrimages. HTS Religion & Society Series Volume 2. Cape Town; Durbanville: AOSIS, 2018.