QUESTION: I was able to understand the comparative seriousness between the five rebellious sins and the sin of slandering the True Dharma. Could you explain what slandering the True Dharma exactly means?

ANSWER: Grand Master T’ien-t’ai explains in his Commentary on the Brahma-net Sūtra, “The term slander means to go against.” We may say slandering the True Dharma means to go against the teaching of the Buddha. Vasubandhu’s Treatise on the Buddha-nature preaches, “Hate means to go against principle.” It means that to slander the True Dharma equals to cause people to abandon it.

Ken Hōbō-shō, A Clarificaton of Slandering the True Dharma, Writings of Nichiren Shōnin, Doctrine 3, Pages 115.