Full Idea
Know that the Self (Atman) is the rider, and the body the chariot; that the intellect is the charioteer, and the mind the reins.
Gist of Idea
Self is the rider, intellect the charioteer, mind the reins, and body the chariot
Source
Anon (Upan) (The Upanishads [c.950 BCE], 'Katha')
Book Reference
'The Upanishads', ed/tr. Prabhavananda /Manchester [Mentor 1957], p.19
A Reaction
This strikes me as exactly right. Even my intellectual powers are servants of the self. This suggests the view of the mind as a tool, which does not seem to occur in modern discussions.