erstand if
we examine the conditions in an individual's experience which
make this longing for the divine presence acute, and the
general circumstances of human life which make it a continuous
desire in many people.

There are, to begin with, constant facts of experience which
make the realization of the divine presence not only a satisfaction,
but the indispensable "staff of life" for certain human
beings. In their unfaltering faith in God's enduring and proximate
actuality lies their sole source of security and trust.
For such persons a lapse or a lack of faith is the prelude to
utter collapse. A vague general assurance of the dependability
of the future is, for most people, a prerequisite for a
sane and untroubled existence. Even those who live in unreflective
satisfaction with the fruits of the moment would
find these moments less satisfactory were they not set in a
background of reasonably fair promise. The exuberant optimist,
when he stops to reflect, has a buoyant and inclusive
faith in the essential goodness of man and the universe.
Whitman stands out in this connection as the classic type.
Evil and good were to him indifferently beautiful. He maintained
an incredibly large-hearted and magnanimous receptivity
to all things great or small, charming or ugly, that
lightened or blackened the face of the planet.

While the average man accepts the universe with a less
wholesale and indiscriminate appreciation, yet he does feel
vaguely assured that the nature of things is ordered, harmonious,
dependable, and regular, that affairs are, cosmically
speaking, in a sound state. He feels a vast and comfortable
solidity about the frame of things in which his life is set; he
can depend on the familiar risings and settings of the sun, the
recurrent and assured movement of the seasons. Were this
trust suddenly removed, were the cosmic guarantee withdrawn,
to live would be one long mortal terror. That this is
precisely what does happen under such circumstances, the
voluminous literature of melancholia sufficiently proves.

The sense of insecurity takes various forms. Sometimes
the patient experiences a profound and intimate conviction
of the unreality of the world about him. His whole physical
environment comes to seem a mere phantasy and a delusion.
In some cases he finds himself unmoved by the normal interests
and excitements of men, unable to find any stimulus,
value, or significance in the world.

Esquirol observed