Jon Kabat-Zinn

This is it.

Awareness is not the same as thought. It lies beyond thinking, although it makes use of thinking, honoring its value and its power. Awareness is more like a vessel which can hold and contain our thinking, helping us to see and know our thoughts as thoughts rather than getting caught up in them in reality.

Concentration is a cornerstone of mindfulness practice. Your mindfulness will only be as robust as the capacity of your mind to be calm and stable. Without calmness, the mirror of mindfulness will have an agitated and choppy surface and will not be able to reflect things with any accuracy.