To meditate upon thoughts is simply to be aware, as thoughts arise, that the mind is thinking, without getting involved in the content.

Joseph Goldstein (1944 CE--), Joseph Goldstein, one of the first American vipassana teachers, co-founder of the Insight Meditation Society, author of numerous popular books and resident guiding teacher, and leader of retreats worldwide on insight (vipassana) and lovingkindness (metta) meditation.