Bases on the Saṃyuktāgama as the main textual source, this paper discusses how the principles of ”unfolding of cognition into human beings” and ”detachedly transcending the human world” are thoroughgoing. The discourse consists of the following eight sections. The first is an introduction that opens up with the main research themes and the initial ideas and outline. The second section expounds the thesis in four steps. The third section discusses Buddhist path to liberation in terms of perspectives on human beings, human world, and liberation. As an initial and general understanding of the themes in question, the abovementioned perspectives also act as the preparatory procedure for subsequent analysis. Section four singles out three sūtras from the Saṃyuktāgama to serve as examples to elucidate the main themes. Section five employs sūtra no. 42 of the Saṃyuktāgama with a set of items, i.e. aggregate (skandha), sensory gateway (āyatana), and perceptual factor (dhātu), to unfold the thesis on seven aspects. Through the cultivation processes such as observation, contemplation, and cognition in reality, this section exemplifies the two-fold thoroughgoing principle of its main theme. Section six focuses on sūtra no. 69 of the Sayuktāgama to discuss ”actually existing body” (sakkāya) and the five aggregates. The ”actually existing body” can be unfolded into samudaya-gāminī paṭipadā and nirodha-gāminī paipadā to exemplify the two-fold thoroughgoing principle of its main theme. Based on sūtra no. 295 of the Sayuktāgama, section seven expounds the theme that the composite body one has in this lifetime is not any substance owned by any being. As a result, the two-fold thoroughgoing principle can be exemplified as ”the cause-and-conditioned origination of the world,” and ”the cause-and-conditioned cessation of the world.” The eighth section is the conclusion of this paper. There are six reasons why ”unfolding of cognition into human beings” and ”detachedly transcending the human world” can be thoroughgoing in both cognition and practice. Firstly, neither the conceptualization of substantiality nor any dividing frame of dichotomy is established or accepted at all. Secondly, even though the objects in question are sentient beings, human beings, the world, and human world, one does not take the superficial phenomena of these items in question as the bottom line. On the other hand, one should unfold and scrutinize them as sets after sets of living composites, constituent parts, sensory gateways, and perceptual factors. Thirdly, one should focus on inspecting the temporal process of the living composites and perceptual factors. Consequently, one can further unfold all operational aspects, especially on the momenta in its origin, related conditions, subsequent extended pathways, and the endured sufferings. Fourthly, one will dawn on the realization of the life as a sentient being or human being who is trapped in the flood of conditioned co-arising in the world. Being able to perceive beings as sets of composite beings, one is determined to be detached from the previous conceptualizations of the world, and one crucial strategy is to stop or cease the momenta that push the related conditions entailing further drifting in cyclic rebirth. As a result, one will learn to recognize the principle and pathways in transcending the human world by detaching it on all aspects. Fifthly, not merely lip service, nor does the research focus on the objects or on the surface, out of emic observations and cognition, one practices toward the direction of ceasing both the state of mind and life operations. Lastly, along direction to the flood of cognizing conditioned co-arising, and the direction to the practice of completing cessation, the ”unfolding of cognition into human beings” and ”detachedly transcending the human world” are at the junction of arising and ceasing. Therefore, the principle is thoroughgoing.