The 20th century saw three linguistic revolutions respectively headed by Saussure (1916), Chomsky (1957, 1965) and Cognitive Linguists (1980s). There were also three turns in Western philosophy: Ontological Turn, Epistemological Turn and Linguistic Turn. The basic ideas of Cognitive Linguistics can be reduced into the Kernel Principle (KP in short) "Reality - Cognition - Language", which believes that language is the outcome of interactive embodiment and cognitive processing, with the consideration of both objective and subjective factors. KP is thought to better illustrate the general development of the three linguistic revolutions and the three philosophical turns, thus representing the most advanced frontier in the two fields. This paper, on one hand, offers some more evidences for KP, especially for human factors, and on the other hand, K.P can also be taken as a foundation for Applied Cognitive Linguistics, which will be of great importance in language teaching.