Mental calmness, composure, and evenness of temper, especially in a difficult situation is what the dictionary says. Similar words are composure, calm, level-headedness, self-possession, coolheadedness and presence of mind. Han Shan, the poet-hermit from Cold Mountain, says:
If heaven and earth shift, let them shift.
I shall be sitting happy among the rocks.
In these times great equanimity is not optional – it is a requirement if we want to behave in a compassionate manner full of understanding for our co-humans. To understand this intellectually is important and then there is the next step: daily life. Each of us has to find the source of that which tends to bring us out of balance. Many sages have urged us: “Find the source. You must reach the source without fail. The false ‘I’ will disappear and the real ‘I’ will be realized. The former cannot exist apart from the latter.” (Ramana) In this statement is included a valuable hint at how to find the source: “The former cannot exist without the latter.” Our waking consciousness sense of ‘I’ as a psychological center from which all of our actions spring is a derivative of the universal ‘I’, that in Zen is known as Big Mind. Small mind is of the essence of Big Mind but with blinders on. Remove the blinders by recognizing them. To see myself as an individual and a center that interacts with something ‘other’ out there is to have blinders on. Investigate this state of mind and it will lead you to the state free of attributes, concepts, images and mental formations of all kinds.
Enjoy the ride!