The brain is the physical instrument of the mind or the intellect, and the brain must be controlled. For any event the brain is programmed to decide as per the information received in millions of small pieces. The mind makes thousands of decisions before making a final decision (that too subconsciously) to send instructions to the body part. For example, lifting a child who fell down, driving, playing, cooking or any act whatsoever.
So it is most difficult to control the mind, which is exceptionally dynamic. But it is the techniques that help control the mind. The Visualization, Prayer and Chanting are the techniques, which help control the mind, focus thoughts and connect us to the Soul.
As per the Indian system, there are 4 types of mental processes:
1. Mon (intellect of mind), The act of receiving information,
2. Buddhi, We process the information and relate it to exiting knowledge,
3. Ahankara (ego). We evaluate as per our ego,
4.Chitta (feeling), We judge positively and negatively as per our feelings.
The sage Patanjali says in the definition of Yoga as, Yoga Chitta Vritti Nirodha, i.e., Yoga is the control or neutralization of feelings. The Yoga is the Union, which is in the eternal calmness, beyond the likes and dislikes.
The calming is as per the "So Hans" method, where we control and concentrate our energy and emotions. We know the equation, ENERGY-MIND-BODY are interdependent.
Indian system of Yoga looks at everything as different levels of energy. It is not judgmental in evaluating energy as good or bad, but evaluates decisions and actions as per the ability to decrease ability. We know we are more happy as the energy expands and unhappy as energy contracts. The Yoga doesn't suppress energy, but canalizes it, as with thoughts.