熊十力先生曾批判佛教，謂它強調空寂之體，不能產生恆久與充實的作用，以普渡眾生。他因此提出體用不二理論，以形而上的、終極的實體能產生巨大的作用，以成就世間法與出世間法。體與用是不分離的：體必發而為作用，而作用亦需由體發。這理論因此有經驗世界的由體發用、用由體發的機械性的關係。本文則提出純粹力動作為形而上的、終極的原理，它自身是一超越的活動，作用已含於其中，不必往外面尋求一個體作為發動的根源。體與用不止是不二關係，而且完全地是同一。體即是用，用即是體。在形而上學方面不必設置體用關係或體用論，體與用兩概念亦可被捨棄被解構。

Hsiung Shih-Li has vehemently critizied Buddhism that the latter holds Emptiness as the Ultimate Truth, thereby that this Truth fails to provide sufficient function to initiate a universal salvation of sentient beings. Instead he proposed the theory of non-duality of substance and function, which states that in reality substance produces function and function emantes from substance. This theory, however, inclines to presuppose a mechanical relationship between substance and function, In response to Hsiung, the author proposed the concept of pure vitality as the Ultimate Truth, which is, in essence, a transcendental activity, and so is exactly function itself. There is no need to find elsewhere an origin as substance for function. In this sense, substance and function are not merely non-dual in nature, but rather identify with each other. In consequence, the concepts of substance and function do not have a place on the metaphysical and transcendental level, and the substance-function relationship can also be relinguished.