While the House of Linji was the dominant school of Chan in Song China, another competing stream of Zen arose, the “silent illumination” of the House of Caodong, which would later lead to the Soto school of Japan.  Unlike the House of Linji, the House of Caodong was nearly dead in the Song dynasty, but in the late Song the Caodong master Hongzhi revived it while competing against Dahui of the house of Linji, both students of Yuanwu who wrote and compiled the Blue Cliff Record.  The Caodong put emphasis on seated meditation practice rather than koan contemplation and interviews between masters and students about koan cases.  Linji spoke critically of this very sort of Chan:

There are a bunch of blind bald-headed fools who, having stuffed themselves with rice, sit doing Chan-style meditation practice, trying to arrest the flow of thoughts and stop them from arising, hating clamor, demanding silence, but these aren’t Buddhist ways!

Dahui Zonggao (1089 – 1163 CE) studied for many years with many masters, becoming a gifted expert in Linji Chan but failing to find enlightenment.  His teacher gave him a koan, the question, “Where do all buddhas come from?” and the reply, “The east mountain walks over the water.”  He struggled with it, giving forty nine answers, all of which his teacher rejected.  Then his teacher gave him, “To be and not to be, like a flowering vine clinging to a tree,” somewhat like the flowering hedge of Yunmen.  After six months of contemplation, Dahui was enlightened.  He became famous as a teacher while still with his master, was given honors by the Song imperial court and his following eclipsed all other Buddhists among educated elites during the later Song.

Dahui created the practice of koan introspection, focusing on a single, critical phrase, the “turning word” of each encounter dialog, such as Zhaozhou’s “Nothing,” (Wu/Mu) or Mazu’s “No mind, no Buddha.”  He wrote that Zhaozhou’s “Nothing” is a knife that the individual must use for themselves to cut off their old life of doubt and duality, birth and death.  By focusing on a single phrase of a single koan “as if one’s head is on fire,” Dahui believed that all people, commoners, monks and masters alike, could gain great freedom and insight, and it has nothing to do with intelligence or education.  Rather, we must doubt words and refused to be fooled.

Dahui only used a few koans for each student, teaching that one or two cases could be all an individual needs, which is why he found collections of dozens of cases misleading.  According to traditional sources, Dahui was so worried that koan study was becoming a literary tradition rather than a lived practice that he burned the original wood blocks used to print the Blue Cliff Record and destroyed as many copies of his master’s text as he could, which is why this central koan collection was eclipsed in popularity by the Gateless Gate, which we will turn to soon.

Dahui rejected Chan without koan practices such as Hongzhi’s Silent Illumination, which he argued left delusion much as it is in the individual mind, but he also rejected excessive koan practices of others from the House of Linji.  Dahui attacked Hongzhi’s practice of Silent Illumination as heretical in his sermons, but he also officiated at Hongzhi’s funeral, showing that the two were opposed in their teachings but not bitter enemies.  For Dahui, practicing Buddhism without koans is like a blind man without a walking stick who can’t take a single step forward.  Dahui had a powerful influence on Hakuin, and it is from him and the Japanese Rinzai (Chinese: Linji) school that we get the tradition of contemplating the single sound of one hand clapping  for long periods of time or the sound a tree makes falling in the forest when no one is around.

The Epicureans of ancient Greece and Rome would write, “Death is Nothing to Us” on their tombstones, figuring they weren’t around to see it.  Dahui’s verse before death reads:

Birth is thus.  Death is thus; Verse or no verse, what’s the fuss?

Hongzhi (1091 – 1157), two years younger than Dahui, created Silent Illumination Chan, seated meditation to produce peaceful awareness, telling his students to sit like withered tree stump.  Hongzhi traveled widely, but ended up on Mount Tiantong, where Dogen from Japan studied while in China.  Hongzhi said that enlightenment is “a bright flawless pearl, and inscribing words on it deprives it of value.”  He was successful, though not as much as Dahui, with Song elites and intellectuals.  Hongzhi wrote many works which became central to the revival of the House of Caodong, called Soto in Japan, the main rival of the House of Linji, called Rinzai, emphasizing meditative awareness of stream of thoughts, allowing them to rise and pass away without interfering with them.