This paper investigates the philosophical implications of brain-to-brain interfaces (B2BI), a novel technology that allows for direct brain-to-brain communication. The authors use a post-phenomenological approach to analyze how B2BI challenges traditional philosophical understandings of the individual and the collective. They highlight how digital technologies are increasingly redefining human connection, moving beyond simple communication to encompass shared sensory experiences (taste, touch, even sexual intercourse through teledildonics). B2BI represents a significant step forward, enabling a merging of individuals into a collective living body, a concept largely unexplored in philosophical discourse. The paper employs a two-step post-phenomenological methodology: first, establishing a phenomenological framework for understanding collective subjects and the body; second, analyzing B2BI to reveal how it challenges and reshapes this framework. The authors thus aim to contribute to a deeper understanding of how this technology transforms our sense of self and our relationships with others.

The paper reviews existing phenomenological literature on collective subjects, citing works by Husserl, Heidegger, Scheler, and contemporary phenomenologists. It highlights the debate between the "irreducibility claim" (collective intentionality cannot be reduced to individual intentions) and the "individual ownership claim" (collective intentionality consists of individual intentions). The authors note that these approaches generally maintain an "atomistic" perspective, preserving distinct boundaries between individuals even in cases of shared intentionality. The analysis then expands to encompass the role of technology in shaping the body and subjectivity, drawing upon postphenomenological concepts of embodiment and the blurring of boundaries between humans and technology. The work of Mathiesen, who examines the Borg collective from Star Trek as an example of technologically-mediated merging of consciousness, is discussed, though the authors emphasize that their focus is on the emerging reality of B2BI technology rather than science fiction.

The paper follows a post-phenomenological methodology, combining phenomenological analysis with a close examination of a specific technology. The first part establishes the phenomenological groundwork. It explores the concept of collective subjects, drawing upon Husserl's ideas of "personalities of higher order" and examining contemporary phenomenological discussions of collective intentionality, shared emotions, and bodily memories. The authors discuss the "central problem" of collective intentionality, contrasting the irreducibility and individual ownership claims and critiquing their underlying atomistic perspective. The second part focuses on the body's role in subjectivity, using Husserl's distinction between the living body (Leib) and the body as an object (Körper). Postphenomenology's focus on the non-neutrality of technology and the concept of embodiment relations (where technology becomes integral to lived experience) are introduced. This conceptual groundwork sets the stage for the second methodological step, the analysis of B2BI. The authors describe the technological components of B2BI, explaining how brain activity is decoded from a "sender" and encoded into a "receiver." They delve into the experiments conducted using B2BI, such as the collaborative tasks where one person's brain controls another's hand movements and the 'Brain-Net' experiments that involve multiple senders and a single receiver. This detailed description of B2BI forms the basis for the phenomenological analysis that follows.

The core finding is that B2BI technology fundamentally alters our understanding of individual and collective subjectivity. By enabling the sharing of bodily experiences and actions, B2BI blurs the boundaries between individuals, challenging the atomistic perspective of prior phenomenological research on collective intentionality. The authors analyze how B2BI establishes a new form of embodiment, where the sender's intentionality flows not just through a technology, but directly into the receiver's body. This creates a collective living body, where multiple subjects share and experience the same physical reality. The 'Brain-Net' experiments extend this concept further, demonstrating the potential for a collective body shared by a larger community. The paper highlights how the existing phenomenological and postphenomenological frameworks, which generally assume a stable, bounded subject, need to be revised in light of this new technological capacity. The merging of bodies through B2BI raises fundamental questions about personal identity, agency, and moral responsibility within a collective. The ability of one subject to literally 'walk in the shoes of others' profoundly changes our understanding of social interaction and what it means to live together in society.

The paper's findings directly address the research question of how B2BI impacts our understanding of subjectivity and collectivity. The authors demonstrate that B2BI creates a scenario previously confined to science fiction, directly challenging existing phenomenological accounts that largely maintain an atomistic view of collective experience. The analysis suggests that the concept of a shared collective body necessitates a reconceptualization of collective intentionality, emotions, and agency. The blurring of bodily boundaries raises new ethical considerations regarding personal autonomy, responsibility, and the very definition of individual identity. The creation of a collective living body has significant implications for social ontology, requiring further investigation into how shared bodily experience shapes shared consciousness and shared values.

This paper offers a novel phenomenological analysis of brain-to-brain interfaces, arguing that B2BI technology generates a collective living body shared by multiple subjects. This challenges the traditional atomistic view of collective subjects and necessitates a reframing of phenomenological and postphenomenological understanding of embodiment and subjectivity. Further research should investigate the ethical, social, and psychological implications of this new form of human-technology interaction, exploring its impact on individual identity, agency, and social relations. The emergence of this technology compels a re-evaluation of how we define “living together” in a world increasingly mediated by digital technologies.

The study is primarily a philosophical analysis, not an empirical investigation. The authors acknowledge that the current state of B2BI technology is still in its early stages, and future technological advancements may further complicate the phenomenological issues discussed. The paper primarily focuses on the theoretical implications of B2BI, and further research is needed to explore the practical consequences and potential societal effects of widespread adoption of this technology.