(_d_) Take a picture, representing a landscape, the interior of a
building, an assembly of persons, a square, a triangle or a more
complicated geometrical figure. Look at it well. Then lay it aside. Close
your eyes. Reproduce the picture mentally in detail. Then repose your
mind on the same image to the exclusion of all other thoughts. This is
a more fixed and meditative method and will sharpen the mind wonderfully.
It will also develop the power of conscious Mental Imagery. The
key to Objective Concentration is _Conscious Attention_, remember.


ACTIVE AND PASSIVE MENTATION.

These terms imply two different distinct functions of the human
mind. The active function performs the volitional, voluntary thinking.
It is the conscious focusing of the mind on some mental problem.
Banishing from the mind all thoughts and ideas not in harmony with your
special subject of study implies Active Mentation. This function is used
by the active, wide-awake man in his busy and energetic moments. It
is the key to the development of Will-Power and a vigorous intellect.
You are conscious of effort when you are exercising this function. The
mind becomes exhausted after a great deal of such effort and cries out
for rest, because conscious attention implies close concentration of
thought and can be exercised only by the conscious use of Will-Power. You
ought to be able to concentrate upon one subject of thought, study and
observation with undivided attention and then take your mind off that
subject and put it on something else, at your will. Train your mind to
'give' perfect attention to any subject you like and also to 'shut off'
or inhibit all attention on that subject. The mind is a restless thing
darting from one thing to another, and, like a spoilt child, tiring of
continued attention. But you must, by Will-Exercise, get control over