I've always liked Sri Ramana Maharshi's definition of enlightenment as "a quiet mind."
A quiet mind is calm as a lake on a windless day, and endless as the ocean.
How do we achieve a quiet mind?
Well, we don't have to chase our thoughts around like chickens in the yard. It would be far better, in fact, to befriend them.
When I was on the subway yesterday, a man rolled on with a huge suitcase. Someone told him - in the nicest way possible - that he'd just run over them with his suitcase. "You should have seen me coming with my suitcase," he shrieked back, "and gotten outta my way!"
No one on the subway knew how to respond, because how do you argue with that statement? Do you try to explain how life works, or what a commonsense understanding of fairness would feel like? Clearly, the man was suffering from insecurity and I'm not trying to make fun of him, but I am trying to make a point:
If we're relatively together and sane enough to function, then our thoughts are generally on target. If we find ourselves belaboring our mental activity - thinking thoughts over and over and rehearsing multiple arguments - then it's likely we've internalized an invalidating position.
Like the guy with the suitcase, it's likely there was someone in our lives who was unable to validate common-sense thinking and say "yes, I feel you on that." Instead, they became defensive, and we had to develop multiple ways to argue our position, with limited success.
If we find ourselves talking and talking in our heads, then our conversation partner might be an unsupportive companion. The best way to reduce thinking is not to focus on thinking, but to focus on being a wonderful friend to ourselves.
If we say, "I feel you, honey!" or generally vibe in that direction after every thought formation, then our thoughts will become clearer and brighter. We won't wrangle with a thousand ways of saying the same thing - we'll say it once and know it's at least partially on target. And we'll be open to alternate positions because we won't have to defend our own.
We're thinking because we're not listening to ourselves in a loving way. Thinking is not our heart-song; it's only a temporary phase.
When we direct love toward ourselves with every thought, our thinking will naturally subside. We can then trust in God (Love) and God (Love) will direct our course.