Otto here examines the nature and origins of the feelings of awe, eeriness, exultation — what he calls the Mysterium Tremendum — felt when one steps into the presence of the numinous, the “wholly other,” a thing which is much larger and of a different order from ourselves or those things with which we are familiar. This feeling of standing in the presence of holiness is a feeling which is nearly universal, yet which it is difficult to understand and explain. Otto takes up the task and does a great deal to explicate it.
Where Otto is strongest is in his examinations of primitive religious feeling. His work no doubt has much to offer to any student of the origins of religion. His discussions of the universality and importance of the “religious feeling” are of particular value when read alongside the arguments of William James on the same topic.
Otto goes terribly wrong, however, almost every time that he discusses Christianity. He attempts to reduce Christianity to the level of the other world religions while simultaneously extolling it as the great mystical religion. The tension between these two ideas is particularly evident in the appendices with which the book closes, which find Otto arguing simultaneously that the very heart of Christianity — the Resurrection — is a historical falsehood while claiming for Christianity the position of truest, most complete religion. The two ideas, mutually exclusive, cannot stand together.
I recommend reading this book for Otto’s comments on the origins of religion in the feeling of awe at the transcendent and eternal “Other.” Beyond that, there are bits and pieces that are interesting or insightful, but not much else.