The objective of our study is to explore scientific creativity with a focus on intellectual (thinking) skills in the cognitive aspect by analyzing scientific theories, which are basically the creativity of historical great scientists, Galileo, Newton, Einstein While our study laid stress on the cognitive domain, exploration of the creativity of great scientists is also connected with affective characteristics (motives, task commitment, etc.) and their environmental factors (incubation period). Great scientists of the science history were aware of the discrepancy issue (...) among different fields of study and long searched for solutions, which they held in their minds. As a result, they created a certain hypothesis using the abstraction strategy in which they leave only the considerations suitable for the world view of the time. Then, they conducted a thought experiment that justified it. The reason why it was difficult for general people to understand was that there was a domain transition beyond materials obtained in the abstraction process. Furthermore, they all had strong motives for the future as well as task commitment. Knowledge is a product of natural selection, and the fusion of knowledge that does not presuppose the unity of knowledge is meaningless. (shrink)