Katha Upanishad

Know the soul as lord of a chariot,
the body as the chariot.
Know the intuition as the chariot driver,
and the mind as the reins.
The senses, they say, are the horses;
the objects of sense the paths.

Those who do not have understanding,
whose minds are always undisciplined,
their senses are out of control,
like the wild horses of a chariot driver.

Those, however, who have understanding,
whose minds are always disciplined,
their senses are under control,
like the good horses of a chariot driver.