Almost all Buddhist scholars in Japan agree that all these characteristic ideas of the Mahayana are systematically traceable in Hinayana literature; and that all the reconstructions and transformations which the Mahayanists are supposed to have put on the original form of Buddhism are really nothing but an unbroken continuation of one original Buddhist spirit and life, and further that even the so-called primitive Buddhism as is expounded in the Pali canons and in the Agama texts of the Chinese Tripitaka, is also the result of an elaboration on the part of the earlier followers of the Buddha. If the Mahayana is not Buddhism proper, neither is the Hinayana, for the historical reason that neither of them represents the teaching of the Buddha as it was preached by the Master himself. Unless one limits the use of the term Buddhism very narrowly and only to a certain form of it, no one can very well refuse to include both Mahayana and Hinayana in the same denomination. And, in my opinion, it is proper, considering the organic relation between system and experience and the fact that the spirit of the Buddha himself is present in all these constructions, it is proper that the term Buddhism should be used in a broad, comprehensive, and inward sense. This is not the place to enter into the details of organic relationship existing between the Hinayana and the Mahayana; for the object of this essay is to delineate the course of development as traversed by Zen Buddhism before it has reached the present form. Having outlined my position with regard to the definition of Buddhism and the Mahayana in general as a manifestation of Buddhist life and thought, or rather of the inner experience of the Buddha himself, the next step will be to see where lies the source of Zen and how it is one of the legitimate successors and transmitters of the Buddha’s spirit. _Zen and Enlightenment_