The nature of the memory is to hold an impression, agreeable or disagreeable, and therefore a person holds a thought in mind, whether it is beneficial to him or not, without knowing the result which will come from it. It is like a child who holds a rattle in his hand and hits his head with the rattle and cries with the pain, and yet does not throw the rattle away. There are many who keep in their mind a thought of illness or a thought of unkindness done to them by someone and suffer from it, yet now knowing what it is that makes them suffer so, nor understanding the reason of their suffering.

They go on suffering and yet hold on in memory the very source of suffering. Memory must be one's obedient servant; when it is a master then life becomes difficult. A person who cannot throw away from his memory what he does not desire to keep in mind is like a person who has a safe, but the key of that safe he has lost. He can put in money, but he cannot take it out. All faculties in man become invaluable when a person is able to use them at will, but when the faculties use the person, then he is no longer master of himself.

Concentration is taught by the mystics in order to exercise the will, making it capable of making use of all faculties. A person with will-power can remember what he wishes to remember and can forget what he wishes to forget. All things that deprive one of one's freedom in life are undesirable. The mind must be free from all bad impressions of life, which take away the rest and peace of life. By concentration one is able to hold a certain thought one desires and to keep away all other thoughts, and when one is able to keep away all the thoughts one does not wish to think about, it becomes easy to throw away the impressions of years, if one wishes to forget them. Bad impressions, however old and intimate, are like rubbish accumulated, which should be removed in order to make the house clean.

The human heart is the home of the soul, and upon this home the comfort and peace of the soul depends.