This paper explains the true nature and context of Sejong`s “view of jeong-eum language.” Jeong-eum (正音 proper sounds) is the special name for universal letters that can most scientifically express the audible sounds of nature, including the sounds of human speech. By allowing sounds and letters to circulate (流通_Sejong Introduction) through jeong-eum, Sejong made communication between people possible. Based on this perspective, the paper re-stipulated the core formation process of Sejong`s jeong-eum or view of jeong-eum in terms of hieroglyphics, tone and rhythm placement, and agent of communication. The true nature of the view of jeong-eum was illuminated with the principle of convergence between universality and particularity and the principle of convergence between naturalist philosophy and scientific generativism chosen as the background principles. Based on the scientific analysis of sounds and letters, Sejong determined the absolute phonetic value of each grapheme and at the same time captured the dynamism of diverse sounds of speech produced by them, and in so doing, he presented the path of the right world that the “correctness” of jeong-eum should follow while transcending time and space. The true nature of Sejong`s jeong-eum lies in realizing communication between people on the basis of the universality of sounds and letters and in making it possible with music and scientific methodology to have correctness and standards for sounds and letters. Therefore such a view of jeong-eum letters is established on the “circulation” spirit where all elements forming the context of letters naturally converge in mutual support.