Let’s say that we are going to engage in a one hour meditation session. After we have performed three rounds of counting our breaths, we still have the core meditation practice ahead of us. The first thing we should do is observe the arising of our thoughts. After a thought has arisen, and before it disappears, this is the “existence” of that thought. The second thing we observe, then, is the existence of each thought. We then observe the cessation of those thoughts. At any moment in our mind, there are all kinds of thoughts arising, abiding and ceasing: some happy in nature, some shorter, some longer. But in the ordinary course of our lives, these are not events that we pay too much attention to. So what we are doing here is observing these three stages of the duration of all the conceptual thoughts, attending closely to their arising, existence, and cessation. These three procedures of observation use the mind to observe itself. Observing our thoughts is not something that we do by employing any other kind of external means such as our visual sense, our sense of touch, or our sense of sound. In this practice we just use the mind to observe itself.
[Depicted from "Life as Practical – Practical Instruction to the Lay Practitioner - Part 29" May 2015, Canada.]