Control of Mind

The ultimate aim of yoga has been described in similar words in various classical texts of India. According to Katha Upanishad, the highest state of yoga is experienced when the senses and manas (lower mental faculty) are held back from their normal activities and the buddhi (pure intellect) is kept undistracted.

An idea similar to this is expressed in the Sutras of Patanjali, the Indian sage, as Yoga chitta vritti nirodhah. This means that yoga is the state of cessation of all fluctuations of the inner instrument of cognition.
 
The Bhagavad Gita another holy text of India also says ‘through the practice of yoga the mental activity is restrained and the individualised soul or Atma perceives the Supreme Atma’.

To further elucidate the idea, the Katha Upanishad with a lofty and imaginative simile states :
Atmanam rathinam viddhi, sariram eva tu
Buddhim tu sarathim viddhi, manah pragraham eva cha
Indriyani layany – ahur vishayams – tesu –gocharam
Atmendriyamanoyuktam bhoktety – ahur manishinah

Know your body for a chariot and the soul as the master of the chariot. Know the intellect as higher than the mind and the soul as the highest.