"Sincerity", that is, "not-deceiving" or "putting forth one's whole being", is, according to Rinzai, "the whole being in action" (zentai sayu), in which nothing is kept in reserve, nothing is expressed under disguise, nothing goes to waste. When a person lives like this, he is said to be a golden-haired lion; he is the symbol of virility, sincerity, whole-heartedness; he is divinely human; he is not a manifestation but Reality itself, for he has nothing behind him, he is "the whole truth," "the very thing"

Zen ans Japanese culture, love of nature, p. 349