The sermons here preserved are mere fragments of those delivered during the thirty-seven years of Hui-nêng’s active missionary life. Even of these fragments how much is to be regarded as genuine and authoritative is a question we cannot at present give any definite answer, as the book seems to have suffered the vicissitudes of fates, partly showing the fact that the Zen message of the sixth patriarch was extraordinary in many respects so as to arouse antagonism and misunderstanding among Buddhists. When this antagonism later reached its climax, it is reported that the book was burned up as against the genuine teaching of Buddhism. Except a few sentences and passages, however, which can at once be rejected as spurious, we may take the _Platform Sutra_ on the whole as expressing the spirit and teaching of the sixth patriarch of Zen. The principal ideas of Hui-nêng, which make him the real Chinese founder of Zen Buddhism may be summed up as follows: 1. We can say that Zen has come to its own consciousness by Hui-nêng. While Bodhi-Dharma brought it from India and successfully transplanted it in China, it did not fully realise its special message at the time. More than two centuries were needed before it grew aware of itself and knew how to express itself in the way native to the Chinese mind; the Indian mode in which its original teaching had been expressed as was the case with Bodhi-Dharma and his immediate disciples had to give way as it were to become truly Chinese. As soon as this transformation or transplantation was accomplished in the hands of Hui-nêng, his disciples proceeded at once to work out all its implications. The result was what we have as the Zen school of Buddhism. How did then Hui-nêng understand Zen? According to him, Zen was the “seeing into one’s own Nature.” This is the most significant phrase ever coined in the development of Zen Buddhism. Around this Zen is now crystallised, and we know where to direct our efforts and how to represent it in our consciousness. After this, the progress of Zen Buddhism was rapid. It is true that this phrase occurs in the life of Bodhi-Dharma in the _Records of the Transmission of the Lamp_, but it is in the part of his life on which we cannot put much reliance. Even when the phrase was actually used by Dharma, it was not necessarily considered by him the essence of Zen as distinguishing itself from other schools of Buddhism. Hui-nêng however was fully aware of its signification, and impressed the idea unequivocally upon the minds of his audience. When he made his first declaration of Zen for the benefit of Yin-tsung, the statement was quite unmistakable, “We talk of seeing into our own Nature, and not of practising dhyana or obtaining liberation.”[4.56] Here we have the gist of Zen, and all his later sermons are amplifications of this idea.