Full Idea
Plato had a conception of the emotions and our bodily appetites as being like wild horses, to be harnassed and controlled by reason.
Gist of Idea
Plato saw emotions and appetites as wild horses, in need of taming
Source
report of Plato (Phaedrus [c.366 BCE]) by Peter Goldie - The Emotions 4 'Education'
Book Reference
Goldie,Peter: 'The Emotions' [OUP 2002], p.113
A Reaction
This seems to make Plato the patriarch of puritanism. See Symposium, as well as Phaedrus. But bringing up children can often seem like taming wild beasts.