What is Facebook, and what are its implications for the authenticity of Dasein? Here, Facebook itself replies, declaring; "Facebook helps you connect and share with the people in your life," in pursuit of its "mission ... to give people the power to ... make the world more open and connected." (Hereafter, Facebook is referenced as FB.) Thus FB describes its relation to Dasein using the characteristics: "helps"; "connect"; "share"; "open"; and "power." Structurally speaking therefore, FB believes it "helps" facilitate "open" relationships between people, and positions itself as "the power" that "helps" "connect" "life" on "the world."

With respect to physical extent, FB's claims are accurate, as its digital community involves over 800 million users, and those users span the entire planet. However, these details are not ontologically illuminating, and we observe that FB's response to our question is decidedly ontical, and offers little more than a categorical enumeration. Furthermore, additional investigation of the FB web site reveals no deeper answer, but yields only an expanded feature list. Therefore, the self-descriptions of FB do not open a path towards the answer we seek.

Hence, we reformulate: ontologically speaking, what is the nature of the relation between FB and Dasein? Formulated thus, we see that to uncover the relationship of FB to Dasein, we must investigate existentially; and, comporting ourselves towards investigation in the mode of phenomenological inquiry, we will here apply the concepts and approaches of Martin Heidegger's existential analytic, as outlined in his philosophical opus Being and Time. Using Heidegger's existential analytic, we shall develop a phenomenological perspective on FB, and apply this towards acquiring an appreciation for the potential implications of FB with regards to the authenticity of its users.

In existential terms, FB is computer software, and is therefore equipment. As equipment, FB has equipmental Being, and is ready-to-hand in its everydayness, as something in-order-to, be it something-in-order-to process images, or something-in-order-to communicate with friends. These examples of FB's in-order-to are specific, and here the question arises: what is FB's everyday in-order-to in its generality?

FB has been designed to represent people, social structures, and social interactions, digitally. Within the equipment that is FB, people and interactions are based on user profiles and their relationships. Because FB has equipmental Being, an individual FB user profile ontically determines that user's FB-based equipmental Being, and permits that user to participate in FB activities, including: posting personal data, such as age and address; joining FB groups; posting FB pictures; and, sending FB messages. In this way, the particular equipment whose being is FB takes the notion of an individual Dasein, then expands on that notion to include the concept of inter-Dasein relations, and builds up a digital system of inter-Dasein structures, intended to mirror the social structures that attend Dasein's Being-in-the-world.

In its attempt to mirror the social structures attending Being-in-the-world, it is inarguable that FB has succeeded remarkably in presenting users with a comprehensive digital representation of Being and their own being, and offers remarkably diverse digital forms of social connections, by recreating a world-like experience of the "they," and FB thus has its being as an impressive imitation of social relations in-the-world. However, though FB presents a convincing technological approximation of those aspects it reproduces, what are the limits of this approximation?

What defines FB is its existence: its being is existentiell. Existentially, Dasein has its Being as Being-in-the-world, while FB has its Being as equipment in-the-world. Thus, we immediately perceive that FB can never recreate Being-in-the-world, because the Being of FB is grounded within and limited by its existentiell facticity. FB enables the individual Dasein to study its characteristics ontically and identify the apparently discrete elements of its Being, and then prioritize those elements in-order-to recombine them categorically in the form of an FB profile. But it can never be the case that an FB profile corresponds fully to Dasein's Being-in-the-world. This is because ontology is always prior to the ontical, and "Subjecting the manifold to tabulation does not ensure any actual understanding of what lies there before us as thus set in order." Irrespective of the depth and scope of factical features given digital expression on FB; "We shall not get a genuine knowledge of essences simply by the syncretic activity of universal comparison and classification." This is because Dasein exists outside of and beyond FB, and it is precisely Dasein's existence and the totality of existential Being-in-the-world that FB cuts out, and that FB can never capture because it is digital and equipmental. Quite simply, FB aspires to worldhood but is ontical, and the worldhood-of-the-world is realized only ontologically. Existentially then, we appreciate that when FB "helps you connect and share with the people in your life," the connections it offers are restricted by its Being, which is existentiell.

Thus, we exhibit FB in its generality, and answer the first half of our opening question: phenomenologically, what is Facebook? FB is equipment taken up for-the-sake-of socializing, and its users are involved with the "they" not in the Being of existence, but via the Being of equipment. Through its software, FB permits Dasein to interact only with the digital "they" existentielly, and never existentially.

Appreciating the existentiell nature of FB and FB profiles, we may now address the remainder of our opening question: what are FB's implications for the authenticity of Dasein?

To answer this, we begin with Dasein. Per Heidegger; "The 'essence' of Dasein lies in its existence" -- which is existential. Further to this, we know the 'essence' of FB lies in its existence, which is existentiell and never existential. Accordingly, the existence of FB's characteristics is existentiell, and all of its software features have equipmental Being, and never existential Being. Therefore, an FB user's profile and its FB-relationships with the-FB-"they" have equipmental Being. However, the equipmental Being of FB and FB user profiles is markedly different from the equipmental Being of, for example, a hammer, and this must be addressed.

In existentiell terms, a direct comparison makes the point: a hammer is taken up for-the-sake-of something that precedes our picking it up, for example hammering a nail in-the-world. In contrast, FB is taken up in-the-world for-the-sake-of taking up social interactions within FB's digital FB-world (which presents its own engaging digital representation of people, social structures, and social interactions). In phenomenological terms, the study of a hammer brings out its relationship to Dasein with regards to existential and existentiell structures and elements in-the-world, while the study of FB brings out its relationship to Dasein with regards to existential and existentiell structures and elements in-the-world, as well as existentiell structures and elements in the digital FB-world. So while Dasein comports itself towards a hammer in terms of Dasein's Being and the hammer's equipmental Being, what we must ask is: does Dasein comport itself towards FB in the same way as Dasein comports itself towards a hammer? Does Dasein comport itself to FB primarily in terms of Dasein's Being and FB's equipmental Being?

Here we must examine Dasein's interactions with FB. An individual Dasein takes up FB in its ready-to-handness, creates an FB profile using some subset of their personal characteristics as perceived and prioritized by that Dasein in-the-world, and creates for itself an FB-Dasein in an FB-world. As noted, the FB-world is a software reconstruction of aspects of the worldhood-of-the-world, taken up by hundreds of millions of users around the-world, and these hundreds of millions of users each generate an FB-Dasein to interact with other FB-Dasein via the relations and elements of the FB-world, where that FB-world possesses an ever-increasing number of FB-Dasein and FB-based relations (friends, pictures, notes, conversations, forum messages, et al), and this results in the perpetual occurrence of FB-social-events, amidst the-FB-"they", and propels the evolution of the FB-society. Thusly, the being of FB is endowed with an absorbing FB-social totality; for, even though FB is digital and therefore finite, its finite characteristics appear infinite from the perspective of the individual user, because no single user could ever explore or exhaust all available FB-relations, regardless of the time available. In this way, the-FB-world is an interminable system for the individual Dasein, a fact that obtains regardless of the manner in which FB's factical features are reduced (whether in terms of statistics, or any other ontical quantification). Just as the full totality of experiences and ideation of Being-in-the-world are inaccessible to Dasein, the full FB-totality of FB-experiences and FB-elements are inaccessible to FB-Dasein in-the-FB-world, and Dasein in-the-world.

Therefore, the general nature of Dasein's interaction with FB is such that Dasein takes up FB as the "they" does, immerses itself concernfully inside the seemingly infinite FB-totality, and occupies its FB-Dasein as the-FB-"they" does, in-order-to upload the pictures Dasein feels it is important to upload, post comments and join groups important to Dasein's FB-"they"-self, and judge FB-society as the-FB-"they" does. By such activities, the-FB-"they"-self as the-FB-"they" sustains "itself factically in the averageness of that which belongs to it, of that which it regards as valid and that which it does not, and of that to which it grants success and that to which it denies it," and success has been granted to FB by the "they" and FB-"they", for FB involves over 800 million users, who collectively "spend more than 700 billion minutes per month" in-the-FB-world.

The relevance of this to Dasein proceeds as follows: (i) in its everydayness, Dasein is falling among the "they"; (ii) fallen in the publicness of the "they", the "they"-self of Dasein is consumed by the shared equipment of a common, public world; (iii) today, FB is among the most widely shared public equipment; (iv) hundreds of millions of Dasein spend billions of minutes per month sustaining FB-life and FB-society, and have augmented social-life-in-the-world with social-life-in-the-FB-world; and therefore, (v) the "they" clearly (pre)supposes FB-life is part of "leading and sustaining a full and genuine 'life'," and this brings Dasein's falling "they"-self to unreflectively suppose FB-life is indispensable in its own 'life.'

With this we observe how the being of FB differs from the being of a hammer: in phenomenological terms, Dasein does not comport itself to FB simply in terms of Dasein's Being and FB's equipmental Being. Rather, because "everyday Dasein draws its pre-ontological way of interpreting its Being" from "the kind of Being which belongs to the 'they'," and because FB users possess an FB-Dasein with FB-social-relations amongst the-FB-"they" in a highly developed FB-life that millions of Dasein attend to and aggrandize on a daily and even hourly basis, Dasein may easily -- and, this is the point: often does -- become involved with FB not in a mode of awareness that discerns its equipmental Being, but in terms it has confused with the structures and experiences of Being-in-the-world. Even though FB-Dasein and FB-life have existentiell Being(-in-the-world) and never existential Being(-in-the-world), Dasein today comports itself towards FB as an actual replacement for at least some aspects of social interaction in-the-world, by considering FB an indispensable feature of 'life' -- a conclusion further supported by the fact that the "they" and Dasein's "they"-self currently suppose FB-life is a component of a "full and genuine 'life'," even though prior to 2004 a "full and genuine 'life' " was to be had without FB, because FB did not exist. What are the implications of this for authenticity?

As outlined earlier, Dasein exists outside of and beyond FB, and it is existence that FB cuts out, and that FB can never capture because it is digital and equipmental. However, regardless of the fact that FB can never replace social interaction in-the-world (and can therefore never be a necessary part of 'life'), Dasein today acts as though it can, and is. Accordingly, the impact of FB on Dasein's authenticity is explicated by questioning the most basic FB activity: what happens when Dasein creates and maintains an FB user profile?

In filling out its FB profile, Dasein undertakes a semi-reflective process of concernful selection, and the direction this selection takes is guided by the details FB permits the user to enter, and by the standards of the "they"-self and the-FB-"they"-self in fallenness. This selection adheres to the manner in which the "they" selects, and in this "the real dictatorship of the 'they' is unfolded," for on every FB page and in the representation and presentation of every FB element, the selections of the-FB-"they" intrude visually and structurally. The "they" qua the-FB-"they" select those factical realities that present "them" and FB-"them" in the best possible light. "Everyone is the other, and no one is himself"; and the-FB-"they" uploads pictures in which they and their privileged companions are at their most appealing, and others are not; the-FB-"they" join groups that are exclusive, and embellish what is fashionable; and the-FB-"they" works to post more popular and not more meaningful content than others. Here, all FB-Dasein are involved, and reflect each other, and thus the concernful selection of FB-Dasein amounts to an eternal struggle to "one up" the-FB-other -- an impossibility, because every FB-Dasein is the-FB-other.

Falsity arises as Dasein works to present FB-Dasein in the best of all possible ways, for it selectively and willfully excludes all factical realities that do not contribute to FB-Dasein's superiority in-the-FB-world. This results in an inaccurate and fanciful (digital) representation of Dasein's Being-in-the-world, based on the delusive toiling of Dasein in-the-world, as it works to shore up its own falsity. This falsity inflicts the preclusion of authentic being, because "the being of Dasein is care," where care is a unity of falling, facticity, and existence -- hence the falsity of FB-Dasein negates Dasein's facticity, while at the same time the equipmental Being of FB cuts out existence, and only falling remains. Having concernfully selected only those facts of existence that bring Dasein a malicious and unsustainable contentment, Dasein is delivered unto "a tranquility, for which everything is 'in the best of order' and all doors are open"; and this "Falling ... which tempts itself, is at the same time tranquillizing." By this tranquillizing all moods that diminish contentment are suppressed, and because "Understanding always has its mood," the tranquillizing contentment that arises from selectively constructing an FB-Dasein radically reduces the range of possible understanding to the range of what is understood in contentment. Anxiety, guilt, and conscience are buried and become unrecognizable, and the entire project of Being-in-the-world is obstructed by the comfortable FB-relationships of a comfortable FB-Dasein, whose Dasein in-the-world is narrowed in to comfortable thoughts.

Ultimately, FB is therefore manifest as a technological system that offers a simulacra of worldness in its being, and by this simulacra Dasein's ownmost being is selectively differentiated in to a digitalized FB-being, by way of a process that promotes inauthentic structures and datum, thus inducing users to accept inauthenticity as an axiomatic starting point for self-reflection, and resulting in the equipmentalization of Dasein, and the reduction of opportunities for authenticity to arise in-the-world.

However, though FB encourages inauthenticity and discourages probity, the situation is not irresolvable, for; "inauthenticity is based on the possibility of authenticity" -- and here we observe a route away from FB's tranquillizing fallenness. FB can never reproduce the worldness-of-the-world, and by taking it apart and seeing what it is not, Dasein can move from engaging FB as ready-to-hand to engaging it as present-at-hand, thus opening Dasein to "a clearing-away of concealments and obscurities, as a breaking up of the disguises with which Dasein bars its own way." In a word: untranquillized care remains possible, and there always remains the potential for an FB user to recomport themselves to FB in a manner that befits its equipmentality.