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