Sosan, also known as the Third Zen Patriarch, is a highly revered Chinese Zen teacher who is credited with spreading the teachings of Zen Buddhism throughout China and beyond. While he is generally regarded as a wise and influential figure, there are some notable controversies and criticisms surrounding his teachings and legacy.

One of the main controversies surrounding Sosan is the question of his authorship of the famous Zen text, the Hsin Hsin Ming (or "Faith in Mind"). This text is considered one of the most important and influential Zen texts, but there is debate over whether Sosan was the true author or if it was written by someone else and attributed to him. Some scholars argue that the language and style of the text do not match Sosan's other writings, and that it may have been written by another Zen master. This controversy has been ongoing for centuries and has not been definitively resolved.

Another criticism of Sosan's teachings is that they can be seen as overly intellectual and abstract, lacking the practical and experiential elements that are often emphasized in Zen practice. Some have accused Sosan of promoting a detached and intellectual approach to Zen, rather than emphasizing the importance of direct experience and enlightenment. This criticism is often directed at his famous statement, "The Great Way is not difficult for those who have no preferences," which some see as advocating a passive and uninvolved attitude towards life.

Additionally, Sosan's teachings have been criticized for their emphasis on emptiness and the concept of "no-mind." Some argue that this focus on emptiness can lead to a nihilistic view of the world and a disregard for the value of individual existence. Others have criticized Sosan's teachings for being too focused on the individual and not enough on the interconnectedness of all beings.

Despite these controversies and criticisms, Sosan's teachings and legacy continue to be highly regarded by many in the Zen tradition. His emphasis on the importance of meditation and self-inquiry, as well as his teachings on the nature of reality, have had a lasting impact on Zen practitioners and continue to be studied and debated by scholars and practitioners alike.

In conclusion, while there are some notable controversies and criticisms surrounding Sosan's teachings and legacy, he remains a highly respected and influential figure in the world of Zen Buddhism. His teachings continue to inspire and challenge practitioners, and his legacy lives on through the many Zen masters who have followed in his footsteps.