The key-note is always in harmony with each note, for it has all notes of the scale within it. In the same way the Sufi harmonizes with everybody, whether good or bad, wise or foolish, by becoming like the key-note.

All races, nations, classes and people are like a strain of music based upon one chord, when the key-note, the common interest, holds so many personalities in a single bond of harmony. By a study of life the Sufi learns and practices the nature of its harmony.

He establishes harmony with the self, with others, with the universe and with the infinite.
He identifies himself with another, he sees himself, so to speak, in every other being.
He cares for neither blame nor praise, considering both as coming from himself. If a person were to drop a heavy weight, and in so doing hurt his own foot, he would not blame his hand for having dropped it, realizing himself in both the hand and the foot. In like manner the Sufi is tolerant when harmed by another, thinking that the harm has come from himself alone.
He uses counterpoint by blending the undesirable talk of the friend and making it into a fugue.
He overlooks the fault of others, considering that they know no better.
He hides the faults of others, and suppresses any facts that would cause disharmony.
His constant fight is with the naf, the root of disharmony and the only enemy of man. By crushing this enemy man gains mastery over himself; this wins for him mastery over the whole universe, because the wall standing between the self and the Almighty has been broken down.

Gentleness,
mildness,
respect,
humility,
modesty,
self denial,
conscientiousness,
tolerance and
forgiveness
are considered by the Sufi as the attributes which produce harmony within one's own soul as well as within that of another.

Arrogance,
wrath,
vice,
attachment,
greed and
jealousy
are the six principal sources of disharmony.

Nafs, the only creator of disharmony, becomes more powerful the more it is gratified, the more it is pleased. For the time being it shows its satisfaction at having gratified its demands, but soon after it demands still more until life becomes a burden. The wise detect this enemy as the instigator of all mischief, but everybody else blames another for his misfortunes in life.