Balance of mind is one of the most vital characteristics of a developed jnani or yogi. One who can keep a balanced mind at all times is really a strong and happy person. He is a yogi.
Mental balance is called samadhana in yoga, indicating perfect concentration. It is fixing the mind on atman or the Self without allowing it to run towards objects and have its own way. It is self-settledness. Sri Shankaracharya says in Atma-Anatma Viveka: Whenever a mind engaged in sravana (hearing) and the rest wanders to any worldly object or desire, and finding it worthless, returns to the performance of the three exercises such returning is called samadhana.
A balanced mind is free from anxiety amid pains. There is indifference amid pleasures. There is stability of mind or mental poise. The aspirant or practitioner lives without attachment. He neither likes nor dislikes. He has a great deal of strength of mind and internal peace.
Some aspirants have peace of mind when they live in seclusion, when there are no distracting elements. They complain of great tossing of the mind when they come to a city or mix with people. They cannot practise meditation in a crowded place. This is a weakness. This is not an achievement in samadhana. There is no balance of mind or equanimity in these persons. Only when a student can keep his balance of mind even in a battlefield as he does in a solitary cave in the Himalayas, can he be really said to be fully established in samadhana.
Lord Krishna says in the Bhagavad Gita: Perform all actions, Dhananjaya, dwelling in union with the Divine, renouncing attachments, and balanced evenly in success and failure. This is samadhana. Again you will find in the Gita: The disciplined self, moving among the sense objects with senses freed from attraction and repulsion, mastered by the self, goeth to peace. This is also samadhana.
Pranayama or control of breath checks the velocity of the mind and reduces the quantity of thinking. It removes the dross or impurities in the form of rajas, passion, and tamas, inertia, from the mind. For control of the mind, kumbhaka (retention of breath) is indispensable. You will have to practise kumbhaka daily. You will have to practise puraka, kumbhaka and rechaka (inhalation, retention and exhalation) regularly and rhythmically. Then the mind will become one-pointed.
The period of kumbhaka will increase by systematic practice and proper dietic discipline (light, nutritious, sattwic food). This is the hatha yogic method. The practice of kumbhaka must be done under the guidance of a guru who is a developed yogi.
Uparati (calmness of mind) comes through the practice of sama and dama. Sama is calmness of mind induced by the eradication of vasanas, desires. Renunciation of desires through discrimination constitutes the practice of sama, one of the six-fold virtues (shatsampatti). If a desire arises in your mind, do not give way to it. This will become the practice of sama. Sama is keeping the mind in the heart by sadhana. It is restraint of the mind by not allowing it to externalize or objectify. Such eradication of the desires can be accomplished through contemplation, japa, dhyana, etc.
The restraint of the external activities and the senses is the practice of dama. If you renounce the desire for eating mangoes, it is sama. If you do not allow the feet to carry you to the market to purchase the mangoes, if you do not allow the eyes to see the mangoes and if you do not allow the tongue to taste them, it is dama.
Sama is internal restraint. Dama is restraint of the senses. Though the practice of sama includes the practice of dama, as the senses will not move and work without the help of the mind, yet the practice of dama is necessary. The practice of dama should go hand in hand with sama. You must attack the enemy, desire, from within and without. Then alone can you control the mind.
Take everything as it comes, instead of complaining. This means seizing every opportunity. With such an attitude, you gain a great deal of mental strength and evenness of mind. Irritability vanishes. The power of endurance and patience develop.
If you have to live amid noise, do not complain of it, but profit by it. You may make use of outer disturbances for the practice of concentration. You must develop the power to work undisturbed irrespective of who happens to be nearby. This power comes with practice and it is then useful in a variety of ways. To learn to work under different conditions indicates progress and a great deal of mental control.
Try to rise above not only the thoughts, but the mind itself and the aham vritti, I-ness, that identifies with the body. Try to rise above the empirical mind that creates the I-identification and differences in the world. Then you will be established in your real nature.
Control of mind includes control of buddhi and the annihilation of the little I, the false self-arrogating personality. Lord Jesus says, Empty thyself and I will fill thee. The meaning is: Destroy your egoism. You will be filled with Divinity. This emptying means chitta vritti nirodhah, restraining all the mental modifications. This emptying process or making the mind blank is, no doubt, a trying discipline. But continued and intense practice will bring success. It is only through rigorous discipline that you can rise to that height of strenuous impersonality from which the gifted souls of the world see distant visions and enjoy a higher, divine life.
If the mind is divested of all thoughts of I, then through meditation on atman, after being initiated by a guru and having known the real significance of the Vedas, the mind can be turned back from various pains and made to rest on the blissful atman.
You have to apply your will according to your capacity in your attempt to acquire a balanced mind, otherwise you will get discouraged. This is a very important point. Draw up a program of work or daily routine according to your capacity, and see that it is carried out without fail. Keep the program to a few items. If it has too many items which cannot be executed in a day, which are beyond your capacity, your interest and enthusiasm will slowly wane. Your energy will be dissipated and scattered. Your brain will get exhausted. Whatever you wish to do daily must be carried out to the very letter.
You may fail to maintain the balance in fifty attempts, but from the fifty-first endeavour, you will gain strength of will. You will slowly attain balance of mind. You should not feel discouraged in the beginning. Do not let failures discourage you, but go on doing your best. Do not brood over your faults and failures. Only look at them to see the reason why you failed and then, try again. So doing, you will starve out the tendencies which led you into them; whereas, thinking about them only gives them new strength. Remember the story of Bruce and the Spider. Bruce learnt from the spider. He failed seven times in the war but succeeded in the eighth attempt.