The introduction of the Zen, or contemplative sect, did, in a sense,
both precede and follow that of Shingon. The word Zen is a shortened
form of the term Zenna, which is a transliteration into Chinese of the
Sanskrit word Dhyana, or contemplation. It teaches that the truth is not
in tradition or in books, but in one's self. Emphasis is laid on
introspection rather than on language. "Look carefully within and there
you will find the Buddha," is its chief tenet. In the Zen monasteries,
the chair of contemplation is, or ought to be, always in use.

The Zen Shu movement may be said to have arisen out of a reaction
against the multiplication of idols. It indicated a return to simpler
forms of worship and conduct. Let us inquire how this was.

It may be said that Buddhism, especially Northern Buddhism, is a vast,
complicated system. It has a literature and a sacred canon which one can
think of only in connection with long trains of camels to carry, or
freight trains to transport, or ships a good deal bigger than the
Mayflower to import. Its multitudinous rules and systems of discipline
appall the spirit and weary the flesh even to enumerate them; so that,
from one point of view, the making of new sects is a necessity. These
are labor-saving inventions. They are attempts to reduce the great bulk
of scriptures to manageable proportions. They seek to find, as it were,
the mother-liquor of the great ocean, so as to express the truth in a
crystal. Hence the endeavors to simplify, to condense; here, by a
selection of sutras, rather than the whole collection; there, by
emphasis on a single feature and a determination to put the whole thing
in a form which can be grasped, either by the elect few or by the people
at large.