Also, like earlier Chinese philosophy (Mencius), Tiantai saw an inherent goodness in human nature and the original purity of the human mind (i.e. Buddha-nature).
However, in also acknowledging innate evil in the human mind, Tiantai adopted the perspective of Xunzi (people are inherently bad).
In making these adaptions to Buddhism, Tiantai led to the development of Chan (Zen) Buddhism, which built on the ideas of Tiantai.