The Language of Zen and Human Education Theory: A Mandala of Zen Words and Phrases

This is a Zengo Mandala　（Mandala of Zen words and phrases）
The follow is an excerpt from the book.

13. 無我　(Muga): No-self or selflessness (See Zengo number 3 and number 4)
Muga (no-self or selflessness) is Mushin (see Zengo number 4). It is 誠心誠意（sei-shin-sei-i）, that is, sincerity, pure mind and empty mind. Even if you make a mistake, when you notice it, you will immediately correct it, because you are sincere. However, if you have ego, it will not work, for you will make an excuse, and the Kokoro acts as if somebody else caused the mistake, and this Kokoro interferes with making corrections.
If there is no barrier between you and things and you concentrate on what you are doing, unnecessary and miscellaneous thoughts will not appear. Since you are one with the thing you are dealing with, there is no gap between you and the thing, and you are purely one with it. It is the state of assimilation with the thing. This is called Muga. Muga, which is sincerity, honesty, fulfillment and seriousness, together with pure intellect sets a higher ideal.