Breaking and sparing the Spirit

When I think of what breaking is in mounting a horse,
I think of a parent to a child.
Very often we go into extremes.
Either we smack in the name of discipline or we become slaves to the willfulness of our children.
So what exactly is breaking a horse and what's the purpose?
My idea of explanation at this time is to make the horse response to its master without kicking a fuss and trusting each other 100per cent.
Obeying not out of fear.
How does that sound?
Ok, so why bother to break a horse?
Are horses here to have a relationship with man?
Are they here to be in partership with us?
Well, what i know is that if the horse wants to live side by side to men, he or she must be able to be of help to mankind.
And that is when the trainning comes in! Right?
Just like before we can hired for a job, we have to be able to take orders from our boss.
How and what they expect of us.