Purity of mind requires the destroying of all bad impressions collected there or received at present. One can destroy these impressions by five methods, and the method is chosen according to the impression one has to destroy.

Some impressions need to be washed off from the mind;
some require to be erased from the surface of the mind;
some have to be shaken off like dust from the clothes;
some need to be burnt like the wood in the fire, which after its test by fire turns into ashes;
and some impressions must be drowned, so that they will never come up again.

Bury certain impressions like a corpse, find every way of annihilation that is suited to each impression, so that your mind may be clear. The mind is not only a means of thinking or reasoning, but the king of one's being; and upon the condition of the mind one's health, happiness, and peace in life depend.

Now the question is what to destroy and what to keep in the mind.

Collect and keep all that is beautiful, and destroy all that is void of beauty.
Collect and keep all that is agreeable, and destroy all that has a disagreeable effect upon you.
Collect and keep all that is harmonious, and destroy all that creates disharmony in yourself.
Collect and keep all that is restful, and destroy all that disturbs the peace of your life.

As dust gets into the works of a clock and stops the clock, so the effect produced by all impressions that are void of beauty and harmony and which disturb your peace keeps you from progress.

The mind cannot act properly when it is hindered by impressions which have a paralyzing effect upon it. Life is progress, and stopping from progress is death. Failure does not matter in life. To a progressive person even a thousand failures do not matter. He has before his view success, and success is his, even after a thousand failures. The greatest pity in life is the standstill when life does not move farther. A sensible person prefers death to such a life as that. It is a paralysis of the soul, of the spirit, which is always caused by holding bad impressions in mind. No soul is deprived of happiness in reality; the soul's very being is happiness. Man brings unhappiness upon himself by holding in his hands the clouds of bad impressions, which fall as a shadow upon his soul.

Once a person is able to clear from his mind, by whatever process, the undesirable impressions, a new power begins to spring from his heart, opening a way before him, attracting to him all he requires, clearing from his path all obstacles, and making his atmosphere clear for him to live and move and to accomplish all he wishes to accomplish.