Someone taking our online course asked about negative thoughts in meditation. His concern was whether letting them go would release them into the universe and bring negative results back to him. My answer was absolutely not! When I say "let thoughts be a meaningless activity in the mind", that includes all thoughts, positive or negative. To allow the mind to expand and relax in meditation, we have to release it from its usual focus. During meditation we give the mind a break. We let go of the need to understand, analyze, evaluate and so on. We don't need to pay attention to what our thoughts are about. The type of thoughts we have doesn't matter. It's not necessary to monitor our thoughts in any way and weed out the "wrong kind". All thoughts are equal in meditation!
How we handle thoughts in meditation and outside of meditation is different. Outside of meditation the meaning of our thoughts is important, but even then I feel people become overly concerned about "negative" thoughts. So often people people struggle with them. They fear that negative thoughts or angry feelings will bring them harm and this can cause a lot of suffering. I've seen people become tense and afraid when negative thoughts come, trying hard to replace them with something positive. It becomes a war within.
From my perspective, it's not only frustrating to try to eliminate negative thoughts, it's futile! Life is a mixture of positive and negative. We are a mixture of positive and negative. Trying to change that is trying to change the basic structure of things. Can you get rid of one side of a coin or one pole of a magnet?
I don't mean to say that how we think isn't important. Of course, we'd rather have a positive, uplifting perspective on things, and our attitudes and perspectives definitely do affect us. There can be a value in becoming more aware of our mental patterns, particularly our underlying beliefs and attitudes toward life. When we start to see ourselves more clearly, we are sometimes able to bring about shifts in our way of being and seeing things. But bringing about positive changes goes much deeper than simply trying to stop negative thoughts. It involves the ability to relax into who we are and accept ourselves as we are now -- the positive and the negative. It's a kind of paradox that when we can truly accept ourselves all the way just as we are now, we may very well morph into more compassionate people. That is the natural result of self-acceptance.