[priordine]

Their source isn't an important meditation goal. I'm thinking here of a poisoned arrow - drop the thoughts, as becoming aware of their pedigree is unnecessary.

If I may quote The Basic Method of Meditation by Ajahn Brahm:

During meditation, we are not going to develop a mind which accumulates and holds on to things, but instead we develop a mind which is willing to let go of things, to let go of burdens. Outside of meditation we have to carry the burden of our many duties, like so many heavy suitcases, but within the period of meditation so much baggage is unnecessary. So, in meditation, see much baggage you can unload. Think of these things as burdens, heavy weights pressing upon you. Then you have the right attitude for letting go of these things, abandoning them freely without looking back. This effort, this attitude, this movement of mind that inclines to giving up, is what will lead you into deep meditation. Even during the beginning stages of this meditation, see if you can generate the energy of renunciation, the willingness to give things away, and little by little the letting go will occur. As you give things away in your mind you will feel much lighter, unburdened and free. In the way of meditation, this abandoning of things occurs in stages, step by step. I suppose I'm off to the Intro threads, now that I've broken my silence.