Reverend Haya Akegarasu (1877-1954) was a dynamic and revolutionary individual, and his influence is lasting in the world of Buddhism and Buddhist thinking in modern Japan. He was the most outstanding disciple of Reverend Manshi Kiyozawa, a great Buddhist leader in Japan during the Meiji Era.During the centennial year of Haya Akegarasu's birth, his disciple Rev. Gyomay Kubose felt it timely to translate a lecture that Haya Akegarasu delivered in 1926 entitled The Fundamental Spirit of Buddhism. This lecture was his life interpretation of Gautama Buddha's teaching. In it Rev. Kubose thought that Rev. Haya Akegarasu did not merely explain or objectify his interpretation, he made the teachings live.