Rudolf Otto was a German theologian who developed the notion of the "numinous" to describe the unique, non-rational element of religious experience. His most famous work, The Idea of the Holy, analyzed religious experiences as stemming from a sense of mystery, awe and fascination before a "wholly other" sacred entity. Otto saw the numinous as an a priori category of human consciousness that was irreducible to rational understanding. His work established a paradigm for studying religion as a distinct, non-reducible phenomenon.

2.  Rudolf Otto (September 25, 1869 - March 5, 1937) was
an eminent theologian and religious scholar in the
German Protestant tradition. He is particularly remarkable
for his contribution to the phenomenology of religious
consciousness and his work in the fields of comparative
religion and the history of religion. Based on his research
and observation, Otto developed the notion of the
“numinous” to express the reality of the sacred as the
defining element of religious experience. Otto thus
stressed the unique and essentially non-rational nature of
religious reality, one that he saw as irreducible to other
elements. This stood in stark contrast to the commonly
accepted view of his time that the real essence of religion
lies in universal ethical teachings that can be rationally
justified.

3.  Phenomenology is the study of structures of
consciousness as experienced from the first-
person point of view. The central structure of
an experience is its intentionality, its being
directed towards something, as it is an
experience of or about some object. An
experience is directed towards an object by
virtue of its content or meaning (which
represents the object) together with
appropriate enabling conditions.

4.  Otto's most famous work, The Idea of the
Holy (published first in 1917 as Das
Heilige), is one of the most successful
German theological books of the twentieth
century. It has never been out of print and is
now available in about 20 languages.

5.  The book’s German title, Das Heilige (the Sacred or the
Holy) is followed by the sub-title, “On the irrational element
in the Idea of the Divine and its relationship to the rational
element”—which clearly reflects Otto’s intent to account for
both elements in defining the Sacred, itself the defining
moment of religion. Otto concludes that none of the
notions used to define the Sacred in terms of human
qualities, such as goodness, even heightened to the
utmost degree, was adequate to describe it. Otto coined
the expression of the numinous (from the Latin word for
deity) to describe the unique, qualitatively different content
of the religious experience—one that could not possibly be
expressed in rational language, but only described
analogically through “ideograms” or symbols.

6.  The numinous element was thus linked to the
notion of the Wholly Other—that which
transcends all our rational capacities of
understanding and irresistibly imposes itself
upon perceptive human beings. Otto’s
perspective did not imply any dichotomy
between Christian faith and world religions.
Rather, large portions of his main work consist
of detailed descriptions of how the numinous or
Wholly Other manifests itself in the world’s
various religious traditions.


7.  To further define the content of the numinous, Otto uses
the equally famous expression of the mysterium
tremendum et fascinans, the mystery that is both awe-
inspiring and fascinating. In many ways, the experience of
the “trembling” is the archetypal religious experience, one
that touches the believers directly and makes them
perceive their identity as creatures without any introduction
of rational reasoning.
 Otto felt that in the religious experience, the three
elements of mystery, awe, and fascination (or attraction)
are so intimately related as to form an irreducible synthetic
whole. The paradoxical tension between the fear inspired
by the otherworldly Sacred and the irresistible attraction it
exerts at the same time on the believer was the very
essence of religious consciousness. Since human reason
is unable to break its code, the numinous also appears as
the mystery.

8.  In spite of this, Otto does not reduce the Holy to the non-rational
element any more than he reduces it to the rational and ethical
element. Otto sees the gradual emergence of the ethical
element in combination with the non-rational element as a sign
of a religion’s evolution. That process, according to
him, culminates in Christianity, the most universal religion that
best exemplifies the notion that God is both numinous and
ethical, the angry God and the God of goodness. For Otto, there
is something in the human mind that naturally accepts the
concept that the Deity is good as soon as it is confronted with it.
But the fundamental, raw moment of the Sacred can be found in
the pre-religious consciousness of primitive people in the form of
a totally non-rational, even irrational sense of awe before the
Divine. That paradox does not entirely disappear even as
religious consciousness becomes more refined. Modern and
contemporary attempts to lift that paradoxical tension by
reducing the Holy to the ethical element in fact destroy its very
essence.

9.  In direct response to Kant, Otto’s analysis
culminates with the claim that the Sacred
represents a priori category of the human mind.
The sacred, and with it the religious, represents a
category that is entirely sui generis. It consists of its
rational and non-rational moments, as well as the
sense of the inevitable connection between the two.
Through his description and analysis of the
religious phenomenon, Otto thus believes that he
has isolated an essential mental ingredient missed
by Kant, one that runs deeper and reaches higher
than our pure or practical reason. It amounts to a
capacity to directly and intuitively perceive the
ultimate meaning of things through some obscure
“a priori synthetic knowledge.”

10.  What Otto calls divination is precisely the
quality, developed by some and missing in
many, to perceive the manifestation of the
Divine or, as Christians would put it, listen to
the testimony of the Holy Spirit. The “natural
man,” says Otto, is totally closed to that
realm of the human mind and is thus unable
to understand the essence of religion.

11.  Otto’s work set a paradigm for the study of religion that
focuses on the need to realize the religious as a non-
reducible, original category in its own right. It thus rejects
reductionism of any kind. A further significant contribution
is the inclusiveness of Otto’s approach. His work remains
as a pioneering effort in interreligious dialogue and the
study of comparative religion.
 German-American theologian Paul Tillich acknowledged
Otto's influence on him. Tillich’s early work in the
philosophy of religion owes much to Otto’s “liberating
influence” on him. However, Tillich also criticizes Otto for
failing to integrate the numinous and the secular under the
common banner of “ultimate concern.”

12.  On the other hand, Romanian-American anthropologist Mircea
Eliade used the concepts from The Idea of the Holy as the starting
point for his own 1957 book, The Sacred and the Profane, which
develops the themes discussed by Otto in a very similar way.
 As could be expected, both conservative Christian circles and those
who saw the recognition of a distinct religious element as a distraction
from the social duties of the Church criticized Otto’s approach. Otto’s
paradigm was under much attack between approximately 1950 and
1990, but has made a strong comeback since then.
 Most recently, the great scholar of comparative religion, Ninian
Smart acknowledged the contribution of Otto, while making a
difference between the numinous experience and the mystical
experience. For Smart, the numinous is typical of theism, where God is
perceived as an other-worldly, towering presence, while the mystic
consciousness, typical of Buddhism, represents and inward
experience of oneness with the transcendent. But, as Smart himself
acknowledges, the two are often interconnected, as in negative
theology.