HOW TO IMPROVE INTELLIGENCE

From Self-Development and the Way to Power, by L. W. Rogers (26)

But how is a keen, alert intelligence to be acquired if we do not
possess it? Like any other latent faculty or power it may be evolved.
As the physical strength may be steadily increased by constant
exercise of the muscles, so mind may increase in power by systematic
work. It should be exercised in original thinking. A stated period, if
only a quarter of an hour daily, can be set aside for the purpose. A
book on a serious subject will furnish material but the too common
method of reading, of following the author lazily and accepting
whatever he sets forth as a matter of course, is of little value. One
must read with discrimination, receiving the ideas offered as a
juryman would receive testimony from a witness, considering it from
every possible viewpoint, examining it in the light of known facts,
turning it over in the mind, weighing it thoughtfully, and accepting
or rejecting according to its reasonableness or its lack of reason. In
such mental work for intellectual growth each paragraph can be
considered by itself and only a small portion of the time should be
given to the reading while the remainder is devoted to pondering over
what has been read. Of course a specific study is an advantage and
perhaps nothing is better than to study occultism, thinking deeply
upon the problems of human evolution.

MORE EXERCISES -

Studying life...

Exercising the imagination...