Democritus believes that literary works are the embodiment of a writer's life, especially poetry. He believes that only when writers and artists have a language that can accurately, vividly and truly express objective things can their works be convincing.

Horace believes that the language of a character should conform to the identity and experience of the individual.

Augustine's symbolic language is vivid. To master symbolic language, we must infer and guess with the help of association and imagination.

Dante advocates creating a unified and authoritative national language on the basis of Italian local sayings.

Valerie believes that the essence of symbolic poetry is to make poetry an art of musical language, and musicalization also includes the musicalization of poetic language. "To achieve harmonious rhythm and rhythm, we must meet various rational and aesthetic conditions."

Pound believes that the language of poetry should be as concise as possible "don't use redundant words and adjectives that can't explain anything".

Hume thinks that the living image is the soul of poetry. The difference between poetry and prose lies in images. "Direct language is poetry, because it uses images. Indirect language is prose. " Metaphor is "intuitive language", which accurately describes and conveys all images.

Shklovsk thinks that defamiliarized language has only "poetic function" and loses its social function. Daily life language pays attention to reference function, while literary language pays attention to expression function.

Jacobson believes that poetry is a formal expression of words with independent value. The essence of poetry lies in the "formal expression of poetic language (words)" with the purpose of expression. The realization of poetry (such as aesthetics) provides possibilities. The stronger the poetic function of poetry, the less the language points to the external realistic environment and deviates from the practical purpose, but to the formal factors of itself and the language itself, such as phonology, words and sentences.

Richards believes that scientific language uses symbols, while poetic language uses symbols. Poetic language is an emotional language based on symbols, while scientific language is a symbolic language. Poetic language pays attention to the nature of emotion or attitude aroused, while scientific language pays attention to the correctness of symbol and the authenticity of reference. The scientific statement is only to convey information, regardless of emotional influence. Therefore, scientific statements must be arguable and strictly abide by logical rules. The statement in poetic language is a kind of quasi-statement. Quasi-statement is a statement that cannot be confirmed by empirical facts. The purpose of poetry statement is to express emotion and gain readers' emotional trust.