The illuminating vision is such that the individual differences of
the day vanish in the night of undifferentiated Sameness, the
formless Ground and matrix of all being.  This undifferentiated
Sameness is that mysterious "it" which has been so incontrovertibly
experienced.  The differences disappear, yet they are not completely
abolished in the sense of being annihilated -- transformed back
into Nothing.  They are only negated in thought, in order to make
the undifferentiated Sameness thinkable.  Anyone who ignores the
morning, which brings back the opposites into which the undifferentiated
Sameness is polarized, stands opposite truth as opposite a mirror.
He cannot get away from the thought of "It," the formless Nothing.
Himself grown old (for he has entered into the timeless night of
truth), he stads offosite Nothing, still as "one" confronting the
"other."  But there are always two: the mind that thinks Nothing,
and the Nothing as the truth that is thought.

Anyone, therefore, who supposed he has attained the highest truth
in the thought of Nothing, wherein all differences are extinguished,
and believes that he is superior to those artists who do not get
beyone seeing, in the things of the day, the undifferentiated
Sameness, in all appearances the illustrious origin, and in all
forms the formless Ground -- who, in a word, do not think "abstractly"
enough -- such a person, according to Ryokai, is in danger of going
out of his mind.  He does not realize that the Nothing he thinks
he has attained is only the shadow of the truth, not truth itself.
For this Nothing is still, and always must be, a distinction
predicated by the mind: it is the opposite of This and That, of
the One in contradistinction to the Many; it is a product of
intellectual effort and therefore an empty nothing, a figment of
the brain.

	- Eugen Herrigel, _The Method of Zen_, p.77-79