IN this book I have ventured to write of that which may be
called 'non-rational' or 'supra-rational' in the depths of
the divine nature. I do not thereby want to promote in any
way the tendency of our time towards an extravagant and
fantastic 'irrationalism', but rather to join issue with it in its
morbid form. The 'irrational' is to-day a favourite theme of
all who are too lazy to think or too ready to evade the ar-
duous duty of clarifying their ideas and grounding their con-
victions on a basis of coherent thought. This book, recognizing
the profound import of the non-rational for metaphysic, makes
a serious attempt to analyse all the more exactly the feeling
which remains where the concept fails, and to introduce a
terminology which is not any the more loose or indeterminate
for having necessarily to make use of symbols.

Before I ventured upon this field of inquiry I spent many
years of study upon the rational aspect of that supreme Reality
we call 'God', and the results of my work are contained in
my books, Naturalistische und religiöse Weltansicht (Eng. Tr.
'Naturalism and Religion', London, 1907), and Die Kant-
Friesische Religions-Philosophie. And I feel that no one ought
to concern himself with the 'Numen ineffabile' who has not
already devoted assiduous and serious study to the 'Ratio
aeterna'.

This foreword gives me a very welcome opportunity to ex-
press my thanks to the translator for his care, his remarkable
delicacy of interpretation, and for the valuable supplemen-
tary pages he has added. An English critic has said that 'the
translation is much better than the original'; and to this I
have nothing to object.

RUDOLF OTTO

MARBURG
1923

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