In the Katha Upanishad, the senses are described as horses yoked to the chariot of the body. In regarding the senses as Ashva (horses) what is the inner significance? Ashva means that which is continually restless. It is common knowledge that a horse, whether it is running or standing or sleeping, moves some part of its body or the other all the time. The tail, or the leg, or the back or the nose, some part or other is kept moving. It is because of its restless nature that the horse is called Ashvam. Take the example of a peepal tree: Whether there is any breeze or not its leaves are always rustling. Hence it is called Ashvattha tree.

In ancient times, the rulers used to perform a Yaga (sacrifice) called the Ashvamedha Yaga. Ashva means that which is fickle and restless. Medha means Buddhi (intelligence). Ashva-Medha means ‘fickle-minded.’ The horse that is used in the yaga symbolises a fickle mind. Whoever is capable of capturing and controlling that horse is described as a Dhimanta, a man of heroic intelligence, worthy of meeting in combat. Here we see the esoteric and exoteric meanings of the term Ashvamedha. It is only when both the meanings are synthesised that we get at the whole truth. It is the duty of every person to control the horse-like senses. Only then can he become a hero. Whatever yagas or Yajnas one may perform, whatever scripture he may have mastered, if he has no control over his senses, all these accomplishments are worthless. (SSS Vol.23, p. 42)