1.Introduction

"Dasein" is a core concept in Heidegger's philosophy, denoting "one's own heartfelt activity and firsthand experience of vivid, lived existence." Heidegger's use of "Dasein" challenged long-standing Western philosophical notions of subjectivity, coinciding with the trauma of the time, the repudiation of the prevailing "scientific" spirit, and rationalism. This also gave rise to the development of existentialism and the birth of structuralism. Heidegger's philosophy of existence is integral to understanding this historical phenomenon.

Heidegger defines existence as, "Dasein is that being which can and must explicitly relate to it in one way or another." Its essence cannot be determined by enumerating factual "whats." Instead, its essence lies in the fact that the existence it encompasses (Being) is always to be realized. [1] This definition underscores that, within Heidegger's context, existence is filled with possibilities, and possibility itself is the essential determination of what is called existence. Philosophically, this notion effectively refutes the metaphysical construction of consciousness as the sole determiner of existence in subjective philosophy. It also discards the functional aspects and methodology associated with consciousness. Regarding scientific development, the definition of science as "an interconnected system of true propositions" is imprecise, as scientific activity is also a possible mode of "Dasein." We cannot prove that science is the only or closest mode of existence, and abandoning this outdated view of science can foster its self-development. William D. Blattner argues that, for Heidegger, the concept of "Dasein" signifies that the essence of human existence is neither determined by social reality or culture, nor by nature. Instead, it is determined by the possibility of its existence in the process of self-understanding. [2]

2.Dasein

Heidegger employs the essential attributes of "Dasein" to argue for the fundamental nature of "Being-in-the-World." He distinguishes conventional spatially defined existents from "Dasein," positing the former as existents that conform to the existence of other existents. This differentiation leads to the idea that these existents are separate from the world as a whole, pre-existing within it, which Heidegger refers to as categories. The nature of categories points to the "Being-in" existence construct of "Dasein." According to Heidegger, "Being-in" implies dwelling, being familiar with...being engaged with. This can further be understood as "Dasein" relying on the world's phenomena to exist, dispersing itself within the world to achieve a "Dasein-style existence." Heidegger asserts, "Dasein can grasp that it is always already bound up with the existence of those existents which come face to face with it within its world.[1] It is precisely this that ensures Dasein's inescapable self-comprehension, its self-possession, and establishes solicitude as the primordial way of Being-in-the-world." From this text, it becomes evident that Heidegger firmly adheres to his fundamental stance against subjective philosophy, emphasizing the decentering of consciousness and characterizing consciousness as "Being-in-the-world."

Heidegger aligns with the essential construct of "Being-in-the-World" and focuses on the epistemological aspect of "Dasein." He contends that the most immediate form of interaction is not mere cognitive awareness but practical, manipulative activity - an activity that possesses its own form of "awareness." This interpretation solidifies the inherent mode of knowing in "Dasein," namely, knowing through engagement. Heidegger asserts, "What is at hand encounters us within the world. Thus, the existence of entities which are ready-to-hand is in each case such that it has been disclosed in its kind of Being with the world and in the world." [1] Heidegger argues that the existence of entities engaged with is prior to their ontological nature. He refers to these existents, which come into focus during practical activities, as equipment, essentially things "for-the-sake-of." This context reveals the necessary connection between "Dasein," practical engagement, and the nature of equipment. When using equipment, the focus shifts from the equipment itself to the tasks and purposes for which it is used. In this process, the individual characteristics of equipment are obscured, and the meaning of their existence is intertwined with the many things they guide and are guided by, forming an integrated whole. Heidegger, by theoretically describing the activities of "Dasein" with various existents, refutes the effectiveness of purely observational cognition and argues that "the network of equipment's references is what it is." He counters the dualism between subject and object and the feasibility of constructing epistemology centered on consciousness. Nate Zuckerman argues that: " We should say that his work is only one stage in a necessary and continuing incomplete hermeneutic phenomenology of our existence, which we need to continue to refine and revise in the light of further Revelations as to how our specific ways of being here differ from other possible ways we might imagine, imagine, or encounter." [3]

3.Analysis of the Ontological Foundation of Dasein

3.1.Being-There

Heidegger provides a detailed description of the ontological structure of Dasein and uses the term "Being-there" to refer to what Dasein essentially is, emphasizing the "spatiality" of Dasein in terms of ontological existence. It is a fundamental mode of unfolding and, when Dasein is "here," it can only understand itself by engaging with "there." The meaning of "there" is shifting, oriented by Dasein's involvement, governed by its concern. To elaborate on the unfolding nature of Dasein, Heidegger introduces the concept of "state-of-mind" as a fundamental aspect of Dasein's unfolding state. This term at the level of existents specifically denotes emotions. Heidegger contends that emotions are constant, always present, and the so-called "lack of emotion" is not indifference. It is within this "lack of emotion" that Dasein's true existence is comprehended, revealing existence as a burden. Simultaneously, Dasein longs to give meaning to existence through emotions and fears the annihilation of the so-called "authentic" self, unwilling to surrender existence to emotions. This underscores the omnipresence and inescapability of "state-of-mind," revealing Dasein's reliance on emotions for its daily state of unfolding.

From the presupposition of Being-in-the-world, Heidegger delineates three fundamental properties of state-of-mind: 1. State-of-mind unfolds Being-in-the-world amidst thrownness and does so in a manner of departure that is usually evasive. 2. Emotions have always already unfolded Being-in-the-world as a whole and simultaneously make it possible for us to orient ourselves toward something. 3. From an ontological perspective, state-of-mind has a mode of unfolding directed towards the world, and the entities that come into view do so from this assigned state.[1] Like state-of-mind, understanding constitutes the very constitution of Dasein's existence. Understanding is not a secondary attribute; it is not a methodological level of cognition such as interpretation or writing, which are merely means for understanding and self-development. Understanding does not lead to acquiring some "epiphanic knowledge" of the world itself but is, in fact, the unfolding of the world itself toward the individual. Understanding is fundamentally being-in-the-world. From the above discussion, Heidegger illustrates two fundamental modes in which Dasein unfolds itself and deepens the existential pattern of Dasein based on these modes.

As Liang Jiarong suggests, "In the realm of emotions, Heidegger achieved a significant breakthrough in traditional philosophy. He asserted that knowledge opens up, and emotions open up, but they are different modes of openness. This actually positions Heidegger beyond the ongoing debate between feeling theory and cognitive theory in current emotional research. Moreover, Heidegger even argues that, in terms of openness, emotions have a certain priority over knowledge." [4]

3.2.Falling

Similar to state-of-mind, another concept that serves both as an ontological structure of Dasein and as a way Dasein unfolds itself is "falling." To understand falling, one must begin by examining the condition of thrownness. Thrownness adheres to the structure of Being-in-the-world, dictating that Dasein will be passive, compelled to confront its existence, and driven to surrender itself to "Being-there." This condition, along with Dasein as "being-unto-death," a being full of possibilities, forms the foundation for falling. Falling involves a disappearance into the everyday opinions of the crowd, manifesting in idle talk, curiosity, and ambiguity. Idle talk is a state of average conversation, the way Dasein typically interprets and understands existence. It doesn't unfold with a center but adapts to the unfolding of other Dasein-like existents in its surroundings. Curiosity is a state of restlessness that seeks excitement and change in the surroundings of other existents. It is a fleeting interest, not for the sake of investigation, but merely for the sake of seeing. It does not draw near to the object of curiosity. Both idle talk and curiosity continuously seek and diverge into new possibilities and remain ambiguous. Ambiguity involves the pretense of reality in the discussions of idle talk and the expectations of curiosity. These three modes of falling share the characteristic of disappearing into the common opinions of the crowd, and they lack stable "directionality." They always refer back to themselves. From this characteristic, the essence of falling becomes clear. Falling means that Dasein continually falls into the world it already exists in, becoming deeply entangled in various specific situations, in different times and spaces, profoundly intertwined with them. It is bound by them, structured by them, losing the perspective and capability to gaze beyond the world it exists in. Falling surrenders all to "Being-there," escaping the responsibility of care, unburdening itself of existence, and is seduced into falling. By means of idle talk and curiosity, everything is lightly touched, as if everything is understood and experienced, as if everything in the world is real, secure, and complete. Heidegger states, "The state of non-authenticity does not mean that it is no longer in the world. It actually constitutes a unique way of being in the world, a way in which being is completely apprehended by the 'world' and by others who are 'Being-there' among ordinary people. This 'non-being-in-itself' functions as an active potentiality of the Dasein, which is essentially dissipated in a world. This non-being-in-itself must be understood as the closest mode of being-there. Dasein usually remains in this mode of being." [1]

Dasein, immersed in "public discourse," continually compares and comprehends but overlooks its most authentic potential for "Being-there." It falls into alienation, self-consistency within situations, and forgets the possibilities beyond what "Being-there" offers, entrapped in falling. By describing enticement, comfort, alienation, and self-enclosure as unique modes of falling, we gain insight into the driving force behind falling, which is the shift from authenticity to non-authenticity, from an open realm of possibilities to a closed one, resulting in a loss of so-called "free will" and vitality, as Zhang Zhiwei argues, "When Heidegger distinguishes between the authentic and non-authentic states of Dasein, it does not mean that Dasein's existence was originally authentic and later 'fell' into non-authenticity (falling). Instead, it suggests that whether in an authentic or non-authentic state, both are possibilities of Dasein's 'Being-there.'" [5]

3.3.Care

After discussing various concrete ontological structures of Dasein, Heidegger introduces the concept of "care" to capture the fundamental interconnectedness between these ontological regulations and delineate the overall characteristics of Dasein's Being-in-the-world. Heidegger defines care as "the Being of Dasein means ahead-of-itself-Being-already-in-(the world) as Being-alongside(entities encountered within-the-world)." The various aspects of care encompass existence, facticity (thrownness), and falling. Existence involves Dasein's continuous planning of its potentialities and ongoing strategizing to actualize them.

For Dasein to be possible, it must engage with its existence, engaging its existence before itself. Facticity refers to the realization that the potentialities of Dasein are not groundless but rooted in the factual condition of its thrownness. Falling signifies that Dasein continuously disperses itself within the thrownness and into the ready-to-hand existence that it manipulates. In terms of the unfolding of Dasein, "Care" can be understood through the structures of "existence," "actuality" (thrownness), and "fallenness." Concerning the possibilities of being-in-the-world, "Care" can take two fundamental styles: dealing with things (labor) and dealing with people (solicitude). These three aspects are intertwined in these two modes of existence. Labor transforms mere things into equipment and is guided by various concerns within the activity of using equipment, emphasizing the precedence of labor over observation, the significance of equipment over things, and the integration of equipment with Dasein. However, due to its unique perspective, labor differs from fallenness. A mode of existence that is engaged but does not easily take up equipment is called solicitude. Negative solicitude may manifest as indifference, as if people and equipment were indistinguishable, while positive solicitude may involve assisting others with their current labor. In Heidegger's view, both of these modes of labor are incomplete, and their ultimate purpose is to serve as examples for other Dasein to recognize the true possibility of "Care." It is only in this way that these forms of solicitude align with the ontology of Dasein's existence. Care orients itself towards the future, continues from the past, and falls into the present. Care, in this manner, unfolds Dasein's entire mode of existence. Heidegger asserts, "Care, as the structural whole of originary Being-in, is existentially prior to any actual 'behaviors' and 'states' of Dasein. That is to say, it always already dwells within them. Hence, this phenomenon by no means expresses the priority of 'practical' activities over theoretical ones." [1]

4.Conclusion

Heidegger refutes the essentiality of the "thinking self" subject within consciousness and replaces it with the concept of Dasein. Through extensive description and analysis, as presented above, Heidegger has elaborated the ontological structure of Dasein, demonstrating the precedence and essence of Dasein over consciousness. Heidegger employs various concepts such as "thrownness," "projection," and "fallenness" to illustrate the basic unfolding of Dasein and unifies the ontology of Dasein's existence through the concept of "Care." His unique and forward-thinking philosophy has positioned him as one of the greatest philosophers of the 20th century. His ideas continue to inspire and influence numerous scholars in the fields of humanities and social sciences.