ideas. The only thing to do then is to accept as inevitable the
presence of some distractions, and to realise that to pay attention, it
is necessary to habituate yourself to the ignoring of distractions.

In the accomplishment of this end it will be necessary to apply the
principles of habit formation already described. Start out by making a
strong determination to ignore all distractions. Practise ignoring
them, and do not let a slip occur. Try to develop interest in the
object of attention, because we pay attention to those things in which
we are most interested. A final point that may help you is to use the
first lapse of attention as a reminder of the object you desire to
fixate upon. This may be illustrated by the following example: Suppose,
in studying a history lesson, you come upon a reference to the royal
apparel of Charlemagne. The word "royal" might call up purple, a
Northwestern University pennant, the person who gave it to you, and
before you know it you are off in a long day-dream leading far from the
history lesson. Such migrations as these are very likely to occur in
study, and constitute one of the most treacherous pitfalls of student
life. In trying to avoid them, you must form habits of disregarding
irrelevant ideas when they try to obtrude themselves. And the way to do
this is to school yourself so that the first lapse of attention will
remind you of the lesson in hand. It can be done if you keep yourself
sensitive to wanderings of attention, and let the first slip from the
topic with which you are engaged remind you to pull yourself back. Do
this before you have taken the step that will carry you far away, for
with each step in the series of associations it becomes harder to draw
yourself back into the correct channel.

In reading, one frequent cause for lapses of attention and for the
intrusion of unwelcome ideas is obscurity in the material being read.