By the eleventh century A.D. Hinayana flourished in Ceylon, Burma, Siam and Cambodia. Mystic Buddhism developed in Tibet, Mahayana grew in China. In Japan the whole of Buddhism became the living and active faith of the mass of the people. The present study relates to Japanese Buddhism, as in Japan alone the whole of Buddhism has been preserved. The author presents Buddhist Philosophy in an ideological sequence, but it is not the sequence in the development of ideas. It is rather the systematization of the different schools of thought for the purpose of easier approach, divided into fifteen chapters, the book deals with different schools of Buddhist Philosophy. The author has grouped these schools under two heads: The schools of Negative Rationalism, i.e. the Religion of Dialectic Investigation and the schools of Introspective Intuitionism, i.e. the Religion of Meditative Experience. The author treats these schools in most scientific and elaborate way.