Zurvan: A Zoroastrian Dilemma (1955)
The comparison of religions (1962)
Matter and spirit: their convergence in Eastern religions, Marx, and Teilhard de Chardin (1963)
Christianity and other religions (1964)
Hindu and Muslim mysticism (1969)
Concordant discord: the interdependence of faiths (1970)
Dialectical Christianity and Christian materialism (1971)
Evolution in religion: a study in Sri Aurobindo and Pierre Teilhard de Chardin (1971)
Zen, drugs, and mysticism (1972) (also published as:
Drugs, mysticism and make-believe)
Our savage god : the perverse use of eastern thought (1974)
The City within the Heart (1980)
and his most famous title: Mysticism. Sacred and Profane. An Inquiry into some Varieties of Praeternatural Experience (1957).
We get a glimpse of Zaehner's themes from his preface to Concordant discord:
[The first part of the book] sets the problem of the varieties of mystical experience and an attempt is made to find a solution largely from the Indian sources. In the second half of the book a consideration of the Taoist classics forms the link between the ‘solitary’ mysticism of India and the ‘solidary’ vision of Neo-Confucianism. This leads on to a consideration of Zen and through Zen to the medieval Christian mystics. The rest of the book is devoted to a re-appraisal of Christian doctrine in the light of the religions already studied and of the thought of some ‘fringe’ Catholics of the recent past from Rousseau to Bernanos and Teilhard de Chardin. The ‘golden thread’ that binds the book together is St. François de Sales.
and from this same book, this excerpt:
[C]reatures live on one another, the stronger on the weaker. The mongoose eats mice, the cat eats the mongoose, dog eats cat, and wild beasts eat the dog. Man eats them all. That is the way dharma operates. The whole universe, whether stationary or moving, is the food of life. This is the divinely appointed order, and a sensible man should not be upset by it.
Zaehner is brave enough to envisage the religions sorted according to differing phenomenological experiences of mysticism. Easy enough when you include drug induced states, as he does, but he looks further, bravely.
I suspect Zaehner is onto something. I suspect he does not know what it is , and I for sure, do not know.
Zaehner fell down in the street on his way to Mass. He was dead, with no process of dying.