Philip Kapleau Roshi

Question yourself day and night with the yearning to know and the conviction that you can know. Learn to live the way a fish swims or a bird flies – unself-consciously. Be aware and responsive. In whatever your right hand finds to do involve also your left. Avoid unnecessary judgments. Be modest and unassuming; offer your opinion only when it is asked for. Forget your good deeds and confess your bad ones. And never fail to relate every effect to the cause that produced it.

From  Zen: Merging of East and West  by Philip Kapleau Roshi