鲁道夫·奥托（Rudolf Otto）是二十世纪西方最杰出的宗教学家之一。他在1917年出版的《神圣》中提出的“圣秘学”（numinology）奠定了其宗教学研究的核心地位。他将神圣的本质归为“圣秘”（numinous），注重研究神圣概念的非理性层面，影响极其深远，以致后来的学者对奥托的研究主要就集中在对他的《神圣》及其圣秘学的研究，而他后期另一本比较宗教学的著作《东西方神秘主义》则鲜少被提及。但不容否认，这本书在比较宗教学方面起到了示范作用，十分值得我们学习和研究。《东西方神秘主义》是关于神秘主义本质的比较研究，奥托选取了东西方神秘主义大师商羯罗和埃克哈特为代表，从本体论、价值论、神秘主义的类型、神秘经验的感受等方面进行了比较。本文即通过对这本书的内容分析，来展现奥托如何开展神秘主义研究，并通过探讨奥托这两本著作之间的关系、尤其是“圣秘”和“神秘”两个概念之间的联系，来透视奥托的宗教研究进路。本文的研究将表明，奥托的《东西方神秘主义》一书乃是以他的圣秘学为基础的神秘主义研究，无论在概念上还是研究方法上都对《神圣》有所继承，可以视作圣秘学理论在宗教比较中的一次成功实践。在概念上，奥托在《神圣》中呈现出了宗教的神秘，并且将其视作宗教核心的部分；在比较东西方神秘主义时，他进一步深化了《神圣》中的神秘观念，将“绝异之彼”的神秘作为研究和理解非理性的神秘主义的核心。在研究方法上，《东西方神秘主义》也延续了奥托宗教本质主义的追求、反约化论的立场、宗教现象学和宗教语言学的研究方法。尤其是奥托在《神圣》中提出的圣秘的意向结构、超越结构和两可结构，在《东西方神秘主义》一书中也得到了淋漓尽致的表达。此外，本文还将通过与威廉·詹姆斯等人的神秘主义研究的比较，来评价奥托的神秘主义研究的意义之所在。

Rudolf Otto is one of the most distinguished religious scholars in the West in the twentieth century. The “numinology” proposed by him in The Idea of the Holy published in 1917 laid the core position of his religious studies. He categorizes the divine essence as “numinous”, focusing on the irrational aspects of the Divine, and the influence is so far-reaching that later scholars’ research on Otto mainly focused on his Holy and his numinology, while another his excellent work Mysticism East and West is rarely mentioned. However, the exemplary role played by this book in comparative religion which is worth learning and studying should not be ignored.Mysticism East and West is a comparative study of the nature of mysticism. Otto selected the mysterious masters of the East and West, ?ankara and Meister Eckhart, comparing their mysticism from the ontology, the value theory, the type of mysticism, the feelings of mysterious experience and other aspects. This thesis analyzes the content of this book, shows how Otto conducts mysticism research, and explores the relationship between the two books of Otto, especially the two concepts of “numinous” and “mysterious”, to sum up Otto’s religious research approach.The research in this thesis will indicate that Otto’s Mysticism East and West is a mysticism study based on his numinology. It inherits the Holy both in concept and in research methods. It is his successful practice of the theory of numinous in the comparison of religions. Conceptually, Otto presents the mystery of religion in Holy and regards it as a core part of religion. When comparing East and West mysticism, it deepens the concept of mysterious in Holy and the “Wholly Other” is the core of research and understanding of irrational mysticism. In terms of research methods, Mysticism East and West also continued the pursuit of Otto’s religious essentialism, the position of the anti-reductionism, the research of religious phenomenology and religious linguistics. In particular, numinous’ intentional structure, transcendental structure and contrast-harmony structure that Otto concluded in Holy are also vividly expressed in the later book. In addition, this thesis will evaluate the significance of Otto’s mysticism research by comparing it with the mysticism studies of William James and others.