or Hakuin Ekaku
(1685-1768)
Tokugawa-era reformer and restorer of the Rinzai school of Japanese zen. He is known for his efforts at popularizing Zen among the common people, his systematization of kōan practice into a graded curriculum, his works on secular ethics, his ink drawings, and his invention of the famous kōan: ‘What is the sound of one hand clapping?’
