Not only do happy people endure pain better and take more health and safety precautions when threatened, but positive emotions undo negative emotions.
Martin SeligmanPositive thinking is the notion that if you think good thoughts, things will work out well. Optimism is the feeling of thinking things will be well and be hopeful.
Martin SeligmanOnce a depressed person becomes active and hopeful, self-esteem always improves. Bolstering self-esteem without changing hopelessness, without changing passivity, accomplishes nothing.
Martin Seligman