This article not only examines developments in Bernard Shaw`s scientific and intellectual thinking on evolution and eugenics during the Victorian period comparing these with how his contemporaries reflect changes in thought on the subject and related issues but also explores how Shaw`s ideas on eugenics is perceived in his Back to Methuselah. In the play, Shaw developed the Galtonian eugenic idea of improving the human race with the concept of longevity through his new direction of biological and spiritual imagination rather than the eugenic breeding of the superman. It is a vision of an improved species of long-livers who have pure thoughts and contributes to the Shavian utopia imagined. For the human progress, Shaw`s development of superior human intelligence relates to the scientific concept of eugenic breeding. In this regard, real social progress can be achieved only through every individual`s evolution into god-head. Thus, in Back to Methuselah, Shaw`s vision of human progress can be understood in terms of an exploration of human potentiality attaining godhead and a belief in its possibilities of immortal spirituality by exercise of scientific improvement. Shaw`s Back to Methuselah related to his science of imagination includes metaphysical as well as biological implications based on a concept of longevity with a purpose, an evolutionary appetite. According to Shaw, the life force has not only created man but also inspires man to be creative and to strive towards a higher form of evolution, godhead. Through Back to Methuselah, Shaw looked forward to the evolution of a near-superman, a superman, a super-superman and finally to a state of pure thought in which man would be perfect and free from all his physical impediments. Accordingly, all characters in Back to Methuselah show their metaphysical roles as imaginations of eternal life with understanding of the requirements for real human progress.