From The Science of Yoga by I.K. Taimni
"Dealing with the habits and tendencies
which interfere with the practice of Yoga."
Sadhana Pada, Verse 33
33. When the mind is disturbed by improper thoughts constant pondering over the opposites (is the remedy).
In dealing with the subject of Yama-Niyama, Patañjali has given two Sūtras which are of great help to the practical student of Yoga. The first of these which is being considered gives an effective method of dealing with the habits and tendencies which interfere with the practice of Yama-Niyama. The student who tries to practise Yama-Niyama brings with him the momentum of all kinds of tendencies from previous lives, and in spite of his resolve, the undesirable habits and tendencies in which he has indulged assert themselves strongly and force him to act, feel and think in ways which go against his ideals. What is he to do under these circumstances?
He should ponder constantly over the opposites of the undesirable tendencies when these latter trouble him. In this Sūtra the author has given one of the most important laws of character-building, a law which modern psychology recognizes and recommends in dealing with problems of self-culture. The rationale of this technique for overcoming bad habits and undesirable tendencies, whether they relate to action, feeling or thinking lies in the fact that all evil tendencies are rooted in wrong habits of thought and attitudes and, therefore, the only effective means of removing them completely and permanently is to attack the trouble at its source and alter the thoughts and attitudes which underlie the undesirable manifestations.
As is well known, an undesirable mental habit can be changed only by replacing it by a mental habit of an exactly opposite kind— hatred by love, dishonesty by uprightness. New and desirable mental channels are created by the new thoughts in which mental energy begins to flow in ever increasing measure, starving and gradually replacing the undesirable habits of thoughts and the wrong attitudes which are derived from them. The amount of mental energy required and the time taken will depend naturally upon the strength of the undesirable habit and the willpower of the Sādhaka, but if he puts his heart into the work and perseveres the thing can be done.