It could be said that with the publication of On the Origin of Species in 1859 by Charles Darwin, the debate on organic evolution moved from the realm of contemplation to that of science. However, the theory of natural selection which Darwin proposed as the mechanism of evolution confronted fierce criticisms at that time. Even now natural selection is being debated because of the several problems to be solved. Here I would like to introduce a new mechanism of organic evolution of Kinji Imanishi(1902- ) who has long been critical to Darwinian orthodoxy and proposed a separate evolutionism. According to Imanishi's theory called Sumiwakeron(theory of habitat segregation), organic world is composed of numerous species-societies, which coexist peacefully by dividing habitat they live in and thus make up a harmonious whole-society. Imanishi sees organic change happen while organism goes through the process of dividing and enlarging the living space rather than by the struggle for existence and the survival of the fittest which Darwin asserted. Imanishi thinks that the single and random appearance of mutation on the level of individual which modern orthodox theory proposes as responsible for organic evolution will eventually disappear in population, and therefore that there must be multiple and directional mutations which appear on the level of species if evolution is to be possible. According to Darwin, variation occurs totally by chance indifferently to environment; to Imanishi variation occurs simultaneously toward same direction to all individuals in a species in response to changing environment and only this kind of variation could lead to the appearance of a new species. One of the peculiarities of Imanishi is that he sees no difference among individuals in a species. If observed from inside differences could be seen among individuals; but if seen from outside we will catch the common characters first which all the individuals in the species shares. According to Imanishi, the individual differences are the ones which has nothing to do with the destiny of species or with evolution. If directional mutation occurs simultaneously on the level of species, then the Darwinian struggle for existence among individuals will not happen and there will be no room for natural selection to work. Imanishi proposes a daring idea that such a concurrent-multiple and directional mutation occurs 'when time comes'. When the whole-society which is composed of many species-societies is met with a new circumstance and consequently a species-society in the whole-society must live in a new environment, then all individuals in the species must change themselves to adapt themselves to the changed environment. Under a given circumstance, every individual in a species is expected to respond equally. Therefore if time comes when species must change, individuals must change also. While it can be said that the idea of organic evolution itself is the product of Western culture, it can also be supposed that Imanishi's evolutionary theory is the product of East Asian culture in the sense that evolutionism underwent considerable change and revision to be tuned with East Asian thought and view of Nature. Imanishi's idea that organism possesses a certain consciousness or an internal force is very Eastern-oriented because it reflects the East Asian organic world view. The very point works negatively against Imanishi's theory, however, and the status of Imanishi's hypothesis as a scientific theory came to be questioned because Imanishi's idea threatens the foundation of modern Western philosophy which thoroughly denies any consciousness or vitalism from Nature on the basis of dualism which recognizes matter and mind totally separately. Evolutionary discussion encompasses the time span of 3.2 billion years. Therefore, it is inevitable for the imaginary factors to creep into the theory formation. Then is it not also inevitable for the cultural and ideological factors such as view of Nature of a society of the time to influence the formation of various theories on organic change? In this sense, Imanishi's theory will be worthy of a serious attention and of being considered as an East Asian theory of evolution different from Darwinism.