Your thoughts have no roots, they have no home; they wander just like clouds. So you need not fight them, you need not be against them, you need not even try to stop thoughts.
This should become a deep understanding in you, because whenever a person becomes interested in meditation he starts trying to stop thinking. And if you try to stop thoughts they will never be stopped, because the very effort to stop is a thought, the very effort to meditate is a thought, the very effort to attain buddhahood is a thought. And how can you stop a thought by another thought? How can you stop mind by creating another mind? Then you will be clinging to the other. And this will go on and on, ad nauseam; then there is no end to it.
Don´t fight – because who will fight? Who are you? Just a thought, so don´t make yourself a battleground of one thought fighting another. Rather, be a witness, you just watch thoughts floating. They stop, but not by your stopping. They stop by your becoming more aware, not by any effort on your part to stop them.
Tantra the Supreme Understanding, chapter 2