Hānshān Déqīng (traditional Chinese: 憨山德清, Wade Giles: Han-Shan Te-Ch’ing, "Crazy Mountain, Virtuous Clarity", c. 1546–1623), was a leading Buddhist monk and poet of the late Ming dynasty China.

[3] He is known as one of the four great masters of the Wanli Era Ming Dynasty,[4] along with Yunqi Zhuhong (1535–1613) and Zibo Zhenke (1543–1603) both of whom he knew personally.

[8][9] After hearing Wuji's lectures on the Avatamsaka sutra, Hanshan became very interested in Huayan and the thought of patriarch Qingliang Chengguan.

[13] Then in 1571, at the age of 26, Hanshan set out as a religious wanderer, traveling to different regions and Buddhist temples and monasteries in search of instructions.

He developed strong samadhi (meditative absorption) and had some powerful experiences,[17] called his major awakening or satori by Charles Luk.

[19] In 1577, while on Mount Wutai he decided to copy the entire Avatamsaka Sutra in his own blood (mixed with gold powder).

[20] The copying of the sutra took two years, and at every stroke Hanshan recited the name of Amitabha Buddha, attaining great concentration and reportedly being able to converse during this practice.

In consequence of having organized a successful ceremony to ensure the birth of a male heir to the throne while he was still at Mount Wutai, Hanshan obtained the patronage of the emperor's mother.

This new monastery was called Haiyinsi (Ocean Seal) and it was granted a full copy of the Buddhist canon by the empress dowager.

[23] When relations between the Wanli Emperor and his mother broke down over the choice of heir, Hanshan was caught in a conflict which also included tensions between Daoists and Buddhists.

[27][1] Since the time that Huineng was entombed there, the area had been converted into a meat market by local gangs and the temple's monks were unable to do anything.

At the request of his disciples, Hanshan moved back to Nanhua Temple at Caoxi in 1622 to spend his final years.

On the day he died he called a large gathering of his students and they collectively recited Amitabha's name before Hanshan said:Be not disturbed.

His body was enshrined at Nanhua temple (right next to Huineng's) where it continued to be venerated until the present day with various offerings.

Hanshan drew on the Chan and Huayan doctrine of the "One Mind" (drawn from the Awakening of Faith) as a way to unify all Buddhist schools and all of the three teachings (Buddhism, Confucianism and Daoism).

[47] For Hanshan, all Buddhist methods are but skillful means which point to the One Mind and are to be seen as medicinal treatments to cure the sickness of samsara.

"[52] However, Hanshan also criticized those who studied scriptures without getting the true meaning, becoming caught up in language and solving intellectual puzzles.

[55] While he made use of the huatou method, he did not see it as supreme like the Linji school did, drawing instead on numerous skillful means found in the sutras.

He saw this fundamental teaching reflected in the Lankavatara, which states "sitting quietly in mountains and forests, cultivate your-self in all aspects, and you can see the flowing of illusory thoughts in your own mind," and in a quote by Bodhidharma which states "you have only to stop all external sensations, put to rest all internal turmoil, and keep your mind like a wall, then you can enter the path".

Speaking of the hua-t’ou method, Ta-hui taught his disciples to kill the “sneaky mind” with a cold-blooded hand.

In day or night, while drinking or eating, traveling or staying at home, sitting or lying, entertaining friends, in a quiet moment or at a noisy hour, you must hold on to the hua-t’ou.

[59] After much determined and uninterrupted contemplative practice, which Hanshan calls "a long fight", this method can lead to a breaking down of all concepts and illusions.

Hanshan describes this enlightenment experience as follows: "suddenly you will find that the Lotus-mind breams with a bright light, illuminating the ten directions of the universe.

[8] He may have been influenced on this topic by the work of Yongming Yanshou (whom Hanshan praised) who likewise synthesized Pure-land and Chan from the perspective of the One Mind doctrine.

[63] Hanshan describes this path as follows: "the primary method of Buddha-recitation, the practice of contemplating the pure realm, the guidance of reciting Mahayana scriptures, the determination of making the wish (to be born in the Western paradise), and the charitable deeds that bring about blissful reward.

"[64] In a letter to a vassal prince, Hanshan recommends a simpler form of practice which entails homage to the Buddha, reciting a sutra (like the Longer Sukhāvatīvyūha Sūtra), reciting the Buddha Amitabha's name (three, five, or ten thousand times with a mala) and then dedicating all the merit to be reborn in the pure land.

[66] Hanshan describes this nianfo Chan method as follows:At the very moment the name is uttered, it must be the point at which all doubts and delusions are put to rest.

When you rely steadily on the hua-t'oum all illusions and confused thoughts will be instantly broken down as the in the cutting of knotted threads.

When it is found that the thought arises from the realm of no-birth, then all illusory notions, feelings, and anxieties will at once disappear just like the melting of ice.

It spans from the long doctrinal reflection “Contemplating Mind”[74] to antithetical quatrains composed of balanced couplets: Several of these poems describe the experience of meditation in the hard conditions of a mountain hermitage;[75] others are moral in tone, counselling an attitude of acceptance and the way to social and inner harmony.