That serene and blessed mood
In which ... the breath of this corporeal frame,
And even the motion of our human blood,
Almost suspended, we are laid asleep
In body, and become a living soul:
While with an eye made quiet by the power
Of harmony, and the deep power of joy,
We see into the life of things.
_Tintern Abbey._

"Harmony" and "Joy," it may be noted, are the two words used most
constantly by those who have experienced this vision.

The mystic reverses the ordinary methods of reasoning: he must believe
before he can know. As it is put in the _Theologia Germanica_, "He who
would know before he believeth cometh never to true knowledge." Just as
the sense of touch is not the faculty concerned with realising the
beauty of the sunrise, so the intellect is not the faculty concerned
with spiritual knowledge, and ordinary intellectual methods of proof,
therefore, or of argument, the mystic holds, are powerless and futile
before these questions; for, in the words of Tennyson's Ancient Sage--

Thou canst not prove the Nameless, O my son,
Nor canst thou prove the world thou movest in:
Thou canst not prove that thou art body alone,
Nor canst thou prove that thou art spirit alone,
Nor canst thou prove that thou art both in one:
Thou canst not prove thou art immortal, no,
Nor yet that thou art mortal--nay, my son,