impervious to them and unconscious of them because by the selection of
our life interests we have closed the doors against them.

In either case, whether in the "fringe" of consciousness or entirely
outside of consciousness, these unperceived sensations will be found to
be sensory images that have no connection with the present subject of
thought. They therefore attract, and we spare them, no part of our
attention.

Just as each of our individual sense-organs selects from the multitude
of ether vibrations constantly beating upon the surface of the body only
those waves to the velocity of which it is attuned, so each one of us as
an integral personality selects from the stream of sensory experiences
only those particular objects of attention that are in some way related
to the present or habitual trend of thought.

[Sidenote: _The Man on Broadway_]

Just consider for a moment the countless number and variety of
impressions that assail the eye and ear of the New Yorker who walks down
Broadway in a busy hour of the day. Yet to how few of these does he pay
the slightest attention. He is in the midst of a cataclysm of sound
almost equal to the roar of Niagara and he does not know it.

Observe how many objects are right now in the corner of your mind's eye
as being within the scope of your vision while your entire attention is
apparently absorbed in these lines. You see these other things, and you
can look back and realize that you have seen them, but you were not
aware of them at the time.