惠棟以《中庸》「此仲尼微言也，子思傳其家學，著爲此書，非明《易》不能通此書也」，貫通《中庸》與《周易》之思想，在其《易》著中多見其鑿痕，特別在其《易大誼》，以《易》義闡明《中庸》懿旨，《易大誼》可以視爲惠棟的《中庸》注，也可以說是他的《易》與《中庸》會通的典範。但是，惠棟的會通，把原本高度哲理化的《中庸》思想，帶入強烈象數本色的易學範疇中，並多有附會或曲解者，使之失去其哲學思維的張力與原本多元涵攝融通可能有的開創性詮釋之期望，誠是可惜。 《中庸》之道論，落實在人生修養之中，而惠棟的《易》道觀，則處在元氣本體上來看待。《中庸》的「道」之「性」，在惠棟看來是作爲本體的概念，即陰陽氣合，各正其位，無過不及，不偏不倚，交感諧和之道，也就是致中和、成既濟、贊化育之道，是一種「元、亨、利、貞」的理想德範，儼然成爲一種物化存在的元氣初始之質。《中庸》的「率性之謂道」，惠棟站在天道本位的角度來看這句話，即天道「中和」之「和」，是陰陽諧和之義，即太極陰陽居處正位，和諧交感，彼此相應，致中和而化育萬物。惠棟將《中庸》之「道」，爲了附會其《易》道，刻意忽略在修養工夫這些形下的部份，專注在氣化的本體意義上，對於闡釋《中庸》之大義，仍顯現出強烈的侷限性與濃厚的附會成份，《中庸》原本的哲學思想，反而也被強烈割裂和折損。《中庸》的隱微與慎獨工夫，惠棟則具體的展現在《易》之中，爲一種元氣生發的狀態，即初陽之狀。《中庸》的「中和」與「誠」，惠棟將之與「成既濟定」與「元、亨、利、貞」四德，從宇宙論的角度出發，聯結成共生相應的關係。

"It's Chung Ni's terse and significant statement that Tzu Szu wrote Chung Yung in order to pass on the knowledge inherited from his ancestors, and if you couldn't understand Yi, you would not comprehend the text." In Yi, it's obvious that the author Hui Tung worked to have an insight into thoughts of Chung Yung and Chou Yi. Above all, in his other composition Yi Ta Yi, he used lots of meanings and ideas of Yi to redefine the theme of Chung Yung. Therefore, Yi Ta Yi was considered the annotation of Chung Yung. That is, Yi Ta Yi was an ideal comprehension of Yi and Chung Yung. However, Hui Tung gave the strained interpretation that made Chung Yung, which was highly philosophized step into the realm of Yixue talking about Hsiang and Shu. It's pity that because of much strained explanation and misinterpretation, Hui Tung's work concealed philosophic thoughts of Chung Yung and the possibility of groundbreaking interpretation, which was resulted from multiple understanding of it. The theme of Chung Yung was about the cultivation in human life. In contrary, Yi placed importance on human's vigor. From Hui Tung's sight, the "Hsing" of "Tao" in Chung Yung meant the harmony of Yin and Yang. In other words, Yi and Yang were proper and interactive, also led to neutralization, harmonizing and the breed of creation. The blend of Yi and Yang was an ideal morality of "Yuan, Heng, Li and Chen." It's just like the crystallized existence of the nature of vigor. In Hui Tung's opinion based on the natural law, to see the sentence "Freedom is so-called Tao," he explained that it's "Ho" from "Chung Ho" that meant the harmony of Yi and Yang. That is, Taichi, Yin and Yang are appropriate, interactive and harmonious to breed the whole creation. To strain his interpretation, Hui Tung omitted elements about the cultivation valued by Chung Yung when describing "Tao" in Chung Yung according to Yi. Because Hui emphasized the meaning of the nature of vigor, his delineation of Chung Yung was too limited and strained to reveal the primary thoughts of Chung Yung. However, Hui Tung referred to unapparent and deliberate properties of Chung Yung as a condition of generating vigor just like the rising sun in his writing Yi. Moreover, from the perspective of cosmology, Hui Tung associated "Chung Ho" and "Cheng" in Chung Yung, with "the harmony of Yin and Yang" and the morality of "Yuan, Heng, Li and Chen" to make them become mutually commensal.