Acceptance means that you didn't try to get rid of that thought or feeling, you just let it be. …This probably doesn't sound fun, but it's a necessary step to free yourself from being held prisoner by your bothersome thoughts. Sometimes, the only way past discomfort is through discomfort. So when a tough thought comes up, either during formal mindfulness practice, or at any other point during your day, try not to push it away. What you will come to experience by restraining from avoiding uncomfortable thoughts and sensations is that they will pass all by themselves and in fact at a much quicker speed then when we are actively attempting to not experience them.
Ironic process theory also tells us that trying not to think about something pretty much guarantees the undesired thought will continue to be a regular pest. Psychologists have long known that direct repression doesn’t work.
The above quote seems to be saying that thoughts will disappear by themselves if we just accept them. But that message gets muddied by the next couple sentences:
The goal is not to prevent yourself from having thoughts, feelings or sensations during mindfulness practice. The goal is to notice the distractions that arise and then to gently turn your attention back to your breath.
What is it: thoughts go away by themselves or we take leave of them by directing our attention elsewhere? The advocated acceptance appears to be a momentary stage, contradicted in spirit by the next step: look away.
So it’s okay for thoughts, feelings, and sensations to make an appearance – to show up at the door - but it’s not okay to let them in. It’s about “letting go”, not “letting in”. Acknowledge and move on. This is the approach of distancing and then changing the subject. The net effect is shallow processing of whatever was noticed.*
Here we run into a contradiction: acceptance is supposed to be about “letting it be”, which implies no interference with unfolding and spreading effects of thoughts. However, gently turning your attention back to your breath isn’t a form of letting a thought be but a way of ignoring it. Accepting and ignoring are not the same thing.
* Of course, some guests can be persistent and you can get to know them pretty well just by repeatedly turning them away at the door of awareness.