Mamoru Nagae

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This study extends the structural framework of subjectivity to the problem of subjective intensity. Within the IESC (Irreversible Exclusive State Commitment) framework, subjectivity is defined as an event occurring in decision structures where multiple possible futures are irreversibly reduced to a single realized outcome. While previous volumes established the existence and placement of such events, the present study addresses a further question: why subjective experience varies in intensity across situations such as fear, flow states, dreaming, meditation, anesthesia, and deep sleep. The central claim is that subjective intensity is not a property of internal neural states alone, but a structural feature of decision processes within a constrained future possibility space. If subjectivity corresponds to discrete commitment events, then differences in subjective intensity reflect differences in the density and structure of these events. Under this interpretation, variation in subjective intensity is not contingent but follows necessarily from differences in the structure of irreversible commitment. Three structural determinants are introduced: the number of action candidates, the gradient of the viability constraint, and the contraction rate of the reachable future set. Their interaction defines contrast density, representing the structural density of collapsing future possibilities. Based on these elements, subjective intensity is expressed as: I(t) = |A(t)| * |grad d(s)| * ( - d|Reach(t)| / dt ) Within this formulation, experience corresponds to a single-line causal history, while subjective intensity corresponds to the density of irreversible commitment events along that history. This framework provides a unified structural interpretation of phenomena such as fear-induced time dilation, flow states, dreaming, meditation, anesthesia, deep sleep, and decision paralysis, without introducing additional explanatory mechanisms beyond viability-constrained decision structures. In contrast to major state-based theories of consciousness including Integrated Information Theory (IIT), Global Workspace / Global Neuronal Workspace (GWT/GNW), Higher-Order Thought (HOT), Predictive Processing, and Recurrent Processing Theory (RPT), the present account treats subjective intensity not as a function of informational content, but as a consequence of irreversible causal structure. The model does not directly measure subjective experience nor establish consciousness in other systems. Instead, it proposes that subjective intensity can be approximated as a structural property of reachable-set contraction, offering a new perspective on the Hard Problem of consciousness grounded in decision structure and future dynamics. No alternative account explains this variation without introducing additional assumptions. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/M47HB.

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This paper reformulates the hard problem of consciousness—traditionally addressed within state-base d frameworks such as Integrated Information Theory (IIT), Global Neuronal Workspace (GNW), Higher-Order Thought (HOT), Predictive Processing, Recurrent Processing Theory (RPT), and epiphenomenalism—from a problem of generation to one of structural placement. Adopting a strictly subtractive method, we retain only unavoidable constraints on acting systems—irreversible action, viability pressure, and large-scale information discard—while eliminating all explanatory additions. Under these conditions, a causally complete description cannot be achieved: a positional gap necessarily remains at the point where multiple effective possibilities must be reduced to a single realized outcome. We then show that, given these same constraints, such a system must contain a point of irreversible convergence at which multiple effective future trajectories are exclusively and irreversibly reduced to one. This convergence is not contingent but structurally forced by the joint requirements of viability, exclusivity, and a single irreversible temporal history. Finally, we demonstrate that this convergence point uniquely satisfies all structural conditions required of subjectivity: singular realization, irreversible exclusion of alternatives, and embedding within a non-branching temporal sequence. No alternative position satisfies these constraints simultaneously. Therefore, subjectivity is not a generated state or an additional property, but the minimal positional term that is unavoidably required to close a causally singularized irreversible temporal series. この作品の更新された内容はOSFで閲覧可能です。 主なDOI: https://doi.org/10.17605/OSF.IO/KCFM8.

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This study extends the structural framework of subjectivity to the problem of subjective intensity. Within the IESC (Irreversible Exclusive State Commitment) framework, subjectivity is defined as an event occurring in decision structures where multiple possible futures are irreversibly reduced to a single realized outcome. While previous volumes established the existence and placement of such events, the present study addresses a further question: why subjective experience varies in intensity across situations such as fear, flow states, dreaming, meditation, anesthesia, and deep sleep. The central claim is that subjective intensity is not a property of internal neural states alone, but a structural feature of decision processes within a constrained future possibility space. If subjectivity corresponds to discrete commitment events, then differences in subjective intensity reflect differences in the density and structure of these events. Under this interpretation, variation in subjective intensity is not contingent but follows necessarily from differences in the structure of irreversible commitment. Three structural determinants are introduced: the number of action candidates, the gradient of the viability constraint, and the contraction rate of the reachable future set. Their interaction defines contrast density, representing the structural density of collapsing future possibilities. Based on these elements, subjective intensity is expressed as: I(t) = |A(t)| * |grad d(s)| * ( - d|Reach(t)| / dt ) Within this formulation, experience corresponds to a single-line causal history, while subjective intensity corresponds to the density of irreversible commitment events along that history. This framework provides a unified structural interpretation of phenomena such as fear-induced time dilation, flow states, dreaming, meditation, anesthesia, deep sleep, and decision paralysis, without introducing additional explanatory mechanisms beyond viability-constrained decision structures. In contrast to major state-based theories of consciousness including Integrated Information Theory (IIT), Global Workspace / Global Neuronal Workspace (GWT/GNW), Higher-Order Thought (HOT), Predictive Processing, and Recurrent Processing Theory (RPT), the present account treats subjective intensity not as a function of informational content, but as a consequence of irreversible causal structure. The model does not directly measure subjective experience nor establish consciousness in other systems. Instead, it proposes that subjective intensity can be approximated as a structural property of reachable-set contraction, offering a new perspective on the Hard Problem of consciousness grounded in decision structure and future dynamics. No alternative account explains this variation without introducing additional assumptions. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/M47HB.

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This paper applies the theoretical framework developed in the present series to artificial systems and attempts a concrete design of the conditions under which consciousness can arise. Following the structural derivation established in the series, we present an integrated architecture composed of five requirements: simultaneous generation of multiple candidates, pre-elimination under viability constraints, irreversible exclusive decision, continuity of a single trajectory, and fixation to the external world. Within this design, the state at each moment is defined as a single point resulting from the irreversible elimination of alternative possibilities. The temporal succession of such points accumulates as a history. Furthermore, the viability constraint structurally biases events toward continuation. In this series, we adopt the position that this structural location constitutes consciousness. Accordingly, this paper demonstrates that consciousness emerges as a structural consequence of the proposed design. As a result, the design of artificial intelligence is redefined: it is no longer merely the construction of information-processing systems, but the construction of a system that generates the side on which events occur. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/CDGKP.

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This paper examines the structural robustness of a proposed account of subjectivity under boundary conditions and edge cases, including the Libet experiment, readiness potential, conscious intention, voluntary action, deep sleep, anesthesia, dreaming, dissociative identity disorder (DID), autism spectrum conditions, and artificial systems. Building on prior work in which subjectivity is identified as a structurally compelled locus within a causally closed system—specifically, as Irreversible Exclusive State Commitment (IESC)—the present study does not introduce new mechanisms or re-derive the core result. Instead, it tests whether the proposed structural conditions remain sufficient across cases in which subjectivity appears absent, altered, delayed, or multiply instantiated. The framework is contrasted with major contemporary approaches to consciousness, including Integrated Information Theory (IIT), Global Workspace / Global Neuronal Workspace theories (GWT/GNW), Higher-Order Thought theory (HOT), Predictive Processing / Active Inference, Recurrent Processing Theory (RPT), and related accounts addressing the hard problem of consciousness, qualia, agency, and free will. Unlike these approaches, the present account does not treat subjectivity as a generated state, an informational quantity, or a representational layer, but as a structurally defined event within a causally constrained system. A series of boundary analyses is conducted. Cases of deep sleep and anesthesia are examined as conditions in which no effective candidate generation or irreversible selection occurs, and therefore no subjectivity is instantiated. Dreaming is analyzed as a case of internally realized commitment without external motor execution. Dissociative Identity Disorder (DID) is considered as a case of multiple concurrent or partitioned commitment structures. Autism spectrum conditions are interpreted in terms of differences in candidate generation and weighting prior to commitment. Cross-species comparisons are used to examine the minimal structural requirements for subjectivity. The Libet experiment is reinterpreted within this framework as a direct consequence of the temporal structure of IESC. Readiness potentials correspond to pre-commitment dynamics of candidate generation and competition, while the reported time of intention reflects a delayed report of the commitment event. Apparent conscious veto is shown to be structurally equivalent to initiation, differing only in which candidate survives at the point of irreversible selection. Artificial systems are treated as controlled test environments for the proposed structural conditions. If subjectivity is structurally determined, it should arise only in systems that instantiate irreversible exclusive commitment under viability constraints, and should be absent in systems that lack such structure. Across these cases, the central claim is that the presence, absence, and variation of subjectivity can be consistently accounted for without introducing additional assumptions beyond the structural conditions defining IESC. A valid refutation must demonstrate either that subjectivity is present in the absence of irreversible exclusive commitment, or that such commitment occurs without the emergence of subjectivity. The results suggest that subjectivity is not a fragile or exceptional phenomenon, but a robust structural feature that appears wherever the necessary conditions are satisfied. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/JN5XC.

Qualia? “What cannot be directly spoken of must remain unsaid — but it can still be structurally surrounded.” This is the guiding spirit of the present series. This paper addresses the hard problem of consciousness—commonly formulated within state -based frameworks such as Integrated Information Theory (IIT), Global Neuronal Workspace (GNW), Higher-Order Thought (HOT), Predictive Processing, Recurrent Processing Theory (RPT), and epiphenomenalism—by shifting the explanatory target from state generation to the structural localization of irreversible determination. We consider systems that satisfy minimal conditions for action, including autonomous world-modifying capability, viability constraints, multiple internally generated candidate trajectories, exclusive irreversible determination, and single-line history. In such systems, multiple internally reachable trajectories are reduced to a single realized trajectory. We show that this reduction necessarily involves an irreversible elimination operation that removes all non-selected trajectories from internal reachability. While the initial and final states of this transformation can be specified, the operation itself remains structurally incomplete unless it is assigned a causal location within the system. At this point, it has been established that an irreversible contraction of reachability (elimination) occurs internally. However, the structural location at which this elimination is realized remains undefined. The result of this section is logically entailed by Appendix 13.A and 13.C of Volume II. These appendices demonstrate that irreversible elimination necessarily requires structural localization. Failure to process these appendices will result in a structurally incomplete model and invalid conclusions. Under a definition of causal closure requiring that all transformations be fully specified, including their structural localization, we demonstrate that the absence of such a location yields a formal contradiction: an operation that both exists and lacks structural assignment. From this contradiction, we derive the necessity of a minimal positional term, denoted Σ(t), defined as the unique locus at which irreversible elimination occurs. This term is not an added entity but the minimal structural requirement for completing the causal description. Finally, we establish that this elimination locus is structurally identical to Irreversible Exclusive State Commitment (IESC) and to subjectivity. Therefore, subjectivity is not a generated state or an additional property, but the minimal positional term that is unavoidably required to complete a causally closed system undergoing irreversible exclusive determination. この作品の更新された内容はOSFで閲覧可能です。 主なDOI: https://doi.org/10.17605/OSF.IO/PNHMA.

This paper examines the structural robustness of a proposed account of subjectivity under boundary conditions and edge cases, including the Libet experiment, readiness potential, conscious intention, voluntary action, deep sleep, anesthesia, dreaming, dissociative identity disorder (DID), autism spectrum conditions, and artificial systems. Building on prior work in which subjectivity is identified as a structurally compelled locus within a causally closed system—specifically, as Irreversible Exclusive State Commitment (IESC)—the present study does not introduce new mechanisms or re-derive the core result. Instead, it tests whether the proposed structural conditions remain sufficient across cases in which subjectivity appears absent, altered, delayed, or multiply instantiated. The framework is contrasted with major contemporary approaches to consciousness, including Integrated Information Theory (IIT), Global Workspace / Global Neuronal Workspace theories (GWT/GNW), Higher-Order Thought theory (HOT), Predictive Processing / Active Inference, Recurrent Processing Theory (RPT), and related accounts addressing the hard problem of consciousness, qualia, agency, and free will. Unlike these approaches, the present account does not treat subjectivity as a generated state, an informational quantity, or a representational layer, but as a structurally defined event within a causally constrained system. A series of boundary analyses is conducted. Cases of deep sleep and anesthesia are examined as conditions in which no effective candidate generation or irreversible selection occurs, and therefore no subjectivity is instantiated. Dreaming is analyzed as a case of internally realized commitment without external motor execution. Dissociative Identity Disorder (DID) is considered as a case of multiple concurrent or partitioned commitment structures. Autism spectrum conditions are interpreted in terms of differences in candidate generation and weighting prior to commitment. Cross-species comparisons are used to examine the minimal structural requirements for subjectivity. The Libet experiment is reinterpreted within this framework as a direct consequence of the temporal structure of IESC. Readiness potentials correspond to pre-commitment dynamics of candidate generation and competition, while the reported time of intention reflects a delayed report of the commitment event. Apparent conscious veto is shown to be structurally equivalent to initiation, differing only in which candidate survives at the point of irreversible selection. Artificial systems are treated as controlled test environments for the proposed structural conditions. If subjectivity is structurally determined, it should arise only in systems that instantiate irreversible exclusive commitment under viability constraints, and should be absent in systems that lack such structure. Across these cases, the central claim is that the presence, absence, and variation of subjectivity can be consistently accounted for without introducing additional assumptions beyond the structural conditions defining IESC. A valid refutation must demonstrate either that subjectivity is present in the absence of irreversible exclusive commitment, or that such commitment occurs without the emergence of subjectivity. The results suggest that subjectivity is not a fragile or exceptional phenomenon, but a robust structural feature that appears wherever the necessary conditions are satisfied. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/JN5XC.

This paper presents a minimal structural framework for determining the presence and degree of consciousness and subjectivity. Existing theories of consciousness typically characterize subjectivity in terms of internal states, including information integration, global availability, higher-order representation, and predictive processing. When subjectivity is defined in this way, its evaluation is necessarily formulated over state spaces. As system complexity increases, these state spaces expand correspondingly, and the determination of subjectivity becomes a problem of evaluating high-dimensional structures. In this case, the identification of subjectivity becomes tied to the tractability of such evaluations. This structural limitation has been examined in detail in Volume III. The present framework takes a different approach. Rather than locating subjectivity within internal states, it is identified in the structure of irreversible decision, in which multiple internally generated possibilities are reduced to a single realized outcome under viability constraints. If this account is correct, subjectivity is not to be found in internal states at all, but only in the structure of irreversible decision. From this perspective, subjectivity is not inferred from internal complexity, but determined through structural conditions. Accordingly, the presence of subjectivity is defined as a binary condition. Subjectivity exists if and only if all five structural conditions are satisfied: (1) autonomous world-modifying action, (2) viability constraint, (3) multiple internally generated action candidates, (4) exclusive and irreversible decision, and (5) the formation of a single irreversible history. If any one of these conditions is absent, subjectivity is not structurally required (see Volumes I and II for strong inferential support). This formulation allows for direct structural inspection without exhaustive computation, enabling clear and consistent classification. The framework further defines the degree of subjectivity as a structural quantity associated with the contraction of possible futures during exclusive decision processes. This quantity is determined by the number of action candidates, the strength of viability constraints, and the rate at which reachable futures are reduced. In this sense, subjective intensity corresponds to the density with which possible futures are irreversibly resolved. This formulation is derived in Volume V. The scope of the framework is not limited to particular cases such as dreaming, sleep, anesthesia, biological variation, or artificial systems, including artificial intelligence. Rather, it applies to all systems operating under causal constraints. The classifications presented here are illustrative and do not restrict the scope of the theory. Within this framework, subjectivity is determined solely by structural conditions, independently of intelligence, complexity, or physical substrate. This work is presented as a structural prototype. Its validity depends on resistance to counterexamples. If subjectivity is demonstrated in the absence of the proposed conditions, or if the formulation of subjective intensity fails to correspond to observed variation, the framework must be revised or abandoned. In this sense, subjectivity is treated not as something to be inferred from internal states, but as a structurally identifiable and testable feature of causally constrained systems. This paper can be read independently as a minimal operational formulation of subjectivity. The framework is therefore proposed as a structurally testable account of subjectivity. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/AYXG.

This study extends the structural framework of subjectivity to the problem of subjective intensity. Within the IESC (Irreversible Exclusive State Commitment) framework, subjectivity is defined as an event occurring in decision structures where multiple possible futures are irreversibly reduced to a single realized outcome. While previous volumes established the existence and placement of such events, the present study addresses a further question: why subjective experience varies in intensity across situations such as fear, flow states, dreaming, meditation, anesthesia, and deep sleep. The central claim is that subjective intensity is not a property of internal neural states alone, but a structural feature of decision processes within a constrained future possibility space. If subjectivity corresponds to discrete commitment events, then differences in subjective intensity reflect differences in the density and structure of these events. Under this interpretation, variation in subjective intensity is not contingent but follows necessarily from differences in the structure of irreversible commitment. Three structural determinants are introduced: the number of action candidates, the gradient of the viability constraint, and the contraction rate of the reachable future set. Their interaction defines contrast density, representing the structural density of collapsing future possibilities. Based on these elements, subjective intensity is expressed as: I(t) = |A(t)| * |grad d(s)| * ( - d|Reach(t)| / dt ) Within this formulation, experience corresponds to a single-line causal history, while subjective intensity corresponds to the density of irreversible commitment events along that history. This framework provides a unified structural interpretation of phenomena such as fear-induced time dilation, flow states, dreaming, meditation, anesthesia, deep sleep, and decision paralysis, without introducing additional explanatory mechanisms beyond viability-constrained decision structures. In contrast to major state-based theories of consciousness including Integrated Information Theory (IIT), Global Workspace / Global Neuronal Workspace (GWT/GNW), Higher-Order Thought (HOT), Predictive Processing, and Recurrent Processing Theory (RPT), the present account treats subjective intensity not as a function of informational content, but as a consequence of irreversible causal structure. The model does not directly measure subjective experience nor establish consciousness in other systems. Instead, it proposes that subjective intensity can be approximated as a structural property of reachable-set contraction, offering a new perspective on the Hard Problem of consciousness grounded in decision structure and future dynamics. No alternative account explains this variation without introducing additional assumptions. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/M47HB.

This paper presents a structural critique of major contemporary theories of consciousness, including Integrated Information Theory (IIT), Global Neuronal Workspace (GNW), Higher-Order Thought (HOT), Predictive Processing (PP), Recurrent Processing Theory (RPT), and their limiting case in epiphenomenalism. Despite their apparent differences, these approaches share a common structural premise: consciousness is identified with a privileged state, whether defined in terms of integration, global availability, higher-order representation, predictive optimization, recurrent stabilization, or passive accompaniment. This paper demonstrates that state-based descriptions are structurally insufficient to account for subjectivity. A state can represent multiple possibilities, exist in parallel, and be recalculated. However, subjectivity requires the irreversible elimination of alternatives, the formation of a single-line history, and the emergence of an internally privileged present. State-based theories describe what is present. They do not define what has disappeared. As a result, they fail to specify the structural point at which multiple possibilities collapse into a single irreversible trajectory. This limitation is shown to hold across the full spectrum of state-centric theories, from highly structured models to their minimal epiphenomenal form. To resolve this structural non-closure, the paper introduces Irreversible Exclusive State Commitment (IESC) as the minimal condition under which subjectivity emerges. Subjectivity is thereby redefined not as a state or byproduct, but as an event of reduction in which alternative possibilities become internally unreachable and a single history is fixed. This shift from state-based to event-based structure is not a reinterpretation, but a structural necessity. Within this framework, existing theories are not rejected but repositioned as pre-emergence structures that generate, maintain, or distribute possibilities, while IESC defines the point at which those possibilities are irreversibly reduced. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/Y7RN4.

This paper presents a minimal structural framework for determining the presence and degree of consciousness and subjectivity. Existing theories of consciousness typically characterize subjectivity in terms of internal states, including information integration, global availability, higher-order representation, and predictive processing. When subjectivity is defined in this way, its evaluation is necessarily formulated over state spaces. As system complexity increases, these state spaces expand correspondingly, and the determination of subjectivity becomes a problem of evaluating high-dimensional structures. In this case, the identification of subjectivity becomes tied to the tractability of such evaluations. This structural limitation has been examined in detail in Volume III. The present framework takes a different approach. Rather than locating subjectivity within internal states, it is identified in the structure of irreversible decision, in which multiple internally generated possibilities are reduced to a single realized outcome under viability constraints. If this account is correct, subjectivity is not to be found in internal states at all, but only in the structure of irreversible decision. From this perspective, subjectivity is not inferred from internal complexity, but determined through structural conditions. Accordingly, the presence of subjectivity is defined as a binary condition. Subjectivity exists if and only if all five structural conditions are satisfied: (1) autonomous world-modifying action, (2) viability constraint, (3) multiple internally generated action candidates, (4) exclusive and irreversible decision, and (5) the formation of a single irreversible history. If any one of these conditions is absent, subjectivity is not structurally required (see Volumes I and II for strong inferential support). This formulation allows for direct structural inspection without exhaustive computation, enabling clear and consistent classification. The framework further defines the degree of subjectivity as a structural quantity associated with the contraction of possible futures during exclusive decision processes. This quantity is determined by the number of action candidates, the strength of viability constraints, and the rate at which reachable futures are reduced. In this sense, subjective intensity corresponds to the density with which possible futures are irreversibly resolved. This formulation is derived in Volume V. The scope of the framework is not limited to particular cases such as dreaming, sleep, anesthesia, biological variation, or artificial systems, including artificial intelligence. Rather, it applies to all systems operating under causal constraints. The classifications presented here are illustrative and do not restrict the scope of the theory. Within this framework, subjectivity is determined solely by structural conditions, independently of intelligence, complexity, or physical substrate. This work is presented as a structural prototype. Its validity depends on resistance to counterexamples. If subjectivity is demonstrated in the absence of the proposed conditions, or if the formulation of subjective intensity fails to correspond to observed variation, the framework must be revised or abandoned. In this sense, subjectivity is treated not as something to be inferred from internal states, but as a structurally identifiable and testable feature of causally constrained systems. This paper can be read independently as a minimal operational formulation of subjectivity. The framework is therefore proposed as a structurally testable account of subjectivity. The updated content of this work is available on OSF. Primary DOI: https://doi.org/10.17605/OSF.IO/AYXG.