The implications that follow from identifying life as a closed self-producing recursion coupled to sustained energy throughput, and from the biological evolutionary trajectory as structurally necessary at the ecosystem level under sustained cosmic conditions, are taken in turn. Each positions this account against a standing dispute or empirical question.

*Mechanism and vitalism dissolved.* Vitalism (Bergson, Henri, 1907); (Hans Driesch, 1908) posited a non-material *élan vital* without which dead chemistry could not produce living systems. Mechanism, from Descartes through La Mettrie's *Man a Machine* to the molecular biology revolution, responded that life is just chemistry: extra force is unnecessary. Each view captures something the other misses. Vitalism was tracking the structural fact that life is not reducible to its substrate considered atomistically; mechanism was tracking the fact that no extra substance is required. This account dissolves the binary: life is neither extra force nor mere chemistry but the specific structural configuration (closure plus sustained energy throughput) that uses chemistry as substrate. The vitalists were tracking the configuration's irreducibility; the mechanists were tracking the substrate's sufficiency. Both were partially right; both stop short of naming what configuration the substrate has to enter.

*The biosphere as the unit of evolutionary trajectory.* Standard evolutionary theory has been gradually reorganizing around the recognition that selection acts at multiple levels: individual, kin, group, niche-construction, ecosystem. This account specifies why: directional pressure of dissipation under constraint operates at every level at which closed configurations exist, and the biosphere is the level at which the major evolutionary transitions reorganize the unit of selection. The Gaia hypothesis (James E. Lovelock, Lynn Margulis, 1974), in its rigorous formulations (Lenton, Timothy M., 1998); (Hans Joachim Schellnhuber, 2009), names the self-regulatory feedback that keeps the biosphere within bounds compatible with continued life. This account does not mystify Gaia; it locates the regulation in dissipation pressure on the closed self-producing system that the biosphere as a whole is, with no extra teleological commitment required.

*Universality, descent, and structural identity.* The genealogical universality of known Earth life (shared genetic code, shared chirality, shared chemiosmosis) is standardly read as evidence that all extant life descends from a single ancestor (LUCA, the Last Universal Common Ancestor, or a LUCA-like community in the formulations of Woese -(Carl R. Woese, 1998) and Doolittle -(W. Ford Doolittle, 1999)). This account requires keeping three claims separate. First, that all life shares a *structural identity*: closure plus sustained energy throughput plus heritable specification ([§7.8.2](<7.8.2 What is Required.md>)). Second, that all life shares a *chemical instantiation*: DNA, RNA, ATP, L-amino acids, D-sugars. Third, that all life shares a *genealogy*: descent from one ancestor or community. On the present account the first is necessary; the second is a frozen accident at the chemistry level (Francis H. C. Crick, 1968), since other duality-capable polymers and other amino-acid alphabets would equally satisfy the structural fact; the third is empirical. The standard reading folds all three into one and treats genealogical universality as evidence of structural-and-chemical universality. This account does not. Life elsewhere may share Earth life's structural identity without sharing its chemistry or its genealogy.

*Incumbency and the universality of Earth life.* If first-closures are abductively favored (not strictly necessary) under sustained chemoautotrophic disequilibrium, at the real-but-slight register [§7.8.4](<7.8.4 What is Confirmed.md>) fixes for the origin step, and the conditions are not rare in an old universe, then independent first-closures are less improbable than a rare-accident prior implies. Why, then, does Earth life present a single chemistry? This account licenses an answer the standard reading does not: *ecological incumbency*. The first closure to stabilize at scale acquires priority-effect dominance: its metabolism restructures the chemical environment, its byproducts impose selection on subsequent entrants, its niches preempt competing closures. The Great Oxygenation Event (~2.4 Ga) is one such restructuring; eukaryogenesis (~2 Ga, apparently a single occurrence; Lane -(Lane, N., 2015)) is another; modern microbial-mat priority effects (Tadashi Fukami, 2015) instantiate the same dynamic at smaller scales.

Subsequent independent origins would face an environment no longer chemically neutral, and would either converge on the incumbent's chemistry, persist marginally as symbionts or parasites, or fail to reach scale. The hard-to-place lineages, CPR bacteria, DPANN archaea, giant viruses (Bernard La Scola, Christelle Desnues, ... Didier Raoult, 2008); (Patrick Forterre, 2010), are consistent with all three outcomes; whether any preserve traces of genuinely independent origins (Davies -(Paul C. W. Davies, 2011)'s shadow biosphere program) is empirically open. The universality of Earth life is therefore consistent with both single origin and many origins under incumbency lock-in. The genealogical question is empirical; the structural identity claim does not depend on its resolution.

*Lottery vs. attractor: the empirical signature.* The standard rare-event framing of life's origin treats abiogenesis (the origin of life from non-living chemistry) as a series of independent draws (many trials, low per-trial probability, occasional success) and reaches its rarity verdict by raising a small per-trial probability to a high power. The probability calculus presupposes independence between trials. Abiogenesis does not satisfy that presupposition. Each stage's products are the next stage's inputs: nucleotides condition polymers, polymers condition catalytic networks, networks condition compartmentalized replication. Sustained conditions are required for both regimes (the lottery infrastructure also has to persist) so persistence does not distinguish them. What distinguishes them is sequential dependency between stages: present in abiogenesis, absent in a lottery. The rare-event probability calculus is the wrong calculus, not because the per-step probabilities are higher than supposed, but because the steps are not independent. Component prebiotic reactions are reproducibly demonstrable in the laboratory ([§7.8.4](<7.8.4 What is Confirmed.md>)); several major transitions, multicellularity most clearly, have arisen independently many times across the tree of life and have been reproduced under laboratory selection in tens of generations ([§7.8.4](<7.8.4 What is Confirmed.md>)). Reproducibility from independent starting points is the empirical signature of a sequentially-dependent attractor process, not a lottery. The burden of proof has shifted: the rare-event prior now needs to be defended on its own terms rather than assumed as the default.

*Convergence and non-teleology of cognitive depth.* Earth's biosphere contains within it an instance of structural convergence on cognitive depth from independent evolutionary starting points. Cephalopod molluscs and vertebrates last shared a common ancestor roughly 600 million years ago, before either lineage had developed an integrated nervous system; cephalopods then developed problem-solving, individual recognition, play behavior, and apparent self-modeling along an entirely separate evolutionary trajectory, with distinctive features no vertebrate shares: two-thirds of neurons distributed in the arms, extensive A-to-I RNA editing in neural transcripts (Noa Liscovitch-Brauer et al., 2017), and a genome organization unlike that of any vertebrate (Caroline B. Albertin et al., 2015). The cognitive endpoint is recognizably the same kind of phenomenon (recursive self-modeling under social and ecological complexity) reached through profoundly different molecular and architectural means. At the same time, the lineages that produced this convergence are a small minority of Earth's biomass: bacteria, plants, and most invertebrates have achieved enormous reproductive success across geological time without any cognitive recursion of the kind cephalopods and vertebrates instantiate (Yinon M. Bar-On, Rob Phillips, Ron Milo, 2018). The combination is the one this account predicts. Intelligence is reachable under sustained ecological pressure but not selected for as an end; it is one trajectory among many that closure-bearing lineages can take, instantiated where conditions favor recursive self-modeling and absent where they do not. The astrobiological implication runs from this combination: where ecosystems run long enough under sustained pressure, the cognitive trajectory should be reachable somewhere in the tree of life, even if most of the tree never approaches it.

*Abductive commitment to chemoautotrophic-vent origin.* The framework remains structurally neutral on the specific molecular instantiation of the first closure (chirality, polymer chemistry, exact mineral catalyst) but it does not remain neutral on the kind of site at which the first closure is most likely to have formed. The convergent literature reviewed in [§7.8.4](<7.8.4 What is Confirmed.md>) (Martin, W., and M. J. Russell, 2007); (Lane, N., and W. F. Martin, 2012); (Lane, N., 2015); (Sojo, V., B. Herschy, A. Whicher, E. Camprubí, and N. Lane, 2016); (Weiss, M. C., F. L. Sousa, N. Mrnjavac, S. Neukirchen, M. Roettger, S. Nelson-Sathi, and W. F. Martin, 2016) abductively favors alkaline hydrothermal vents as the most plausible site, because such vents uniquely combine the conditions the framework requires: sustained redox disequilibrium, sustained pH disequilibrium across thin mineral barriers, mineral-catalyzed protometabolic chemistry, and compartmentalization at the right scales, without invoking pre-biological molecular machinery. The commitment is abductive, not deductive: the framework predicts the *kind* of conditions needed, and the chemoautotrophic-vent picture is the best empirical realization of that kind. Rival pictures (warm-little-pond / wet-dry cycling at hot springs, Damer and Deamer -(Damer, B., and D. Deamer, 2020); UV-driven cyanosulfidic chemistry, Sutherland's group; iron-sulfur surface chemistry, Wächtershäuser -(Wächtershäuser, G., 1988)) are not ruled out, but this account predicts they will be found either to converge on the same chemiosmotic mechanism at the closure step or to fall short of producing all three coupled cycles together. The commitment runs at the same modal register as the preference in [§7.6](<7.6 Singularity.md>) for cyclical cosmology over inflationary multiverse: not deductive entailment but the best abductive realization of what the structure requires.

*Astrobiology and the structural prediction of life elsewhere.* On the favoring reading the chapter has developed, the conditions under which the trajectory is favored recur throughout Nature. The laws and the T, S, Φ medium recur by Modal Invariance ([§2.1.7](<2.1.7 Two Readings.md>)), while the gradient conditions recur through the determinate-but-contingent macro-trajectory of [§7.6](<7.6 Singularity.md>) (fixed by the actual cosmological dynamics, not by chance, yet not necessary across worlds). Given those conditions, *some* form of life is favored wherever sustained chemoautotrophic conditions hold long enough. This claim retains the split register established at [§7.8.4](<7.8.4 What is Confirmed.md>): the elaboration of life once a first closure exists is strongly expected, while the first closure itself is favored only at the abductively real-but-slight level the lone Earth datum, with its anthropic confound, can bear. The framework's predictions are structural, not substrate-specific: not carbon, not terrestrial biochemistry, but closure plus sustained energy throughput in whatever medium can sustain it. Whatever realizes closure-plus-throughput counts. Whether such configurations have already been observed (the Drake equation; the Fermi paradox) is an empirical question; the framework's answer is that the configurations are not parochial. Per the relational claim, intelligent life of the kind that elaborates deep recursion requires *populations* of self-modelers in coevolutionary contact; isolated single instances do not deepen the way ecosystems with social structure do. The framework predicts not just life elsewhere but ecosystems elsewhere, and intelligence wherever ecosystems have run long enough under sustained pressure.

The chemoautotrophic-origin prediction ([§7.8](<7.8 Life.md>)) sharpens the astrobiological targets. Bodies with sustained chemical disequilibrium and redox couples are the natural candidates: Mars in its early wet period, when liquid water and serpentinization could have sustained the same chemistry as Earth's vents; Europa, with its subsurface ocean and likely seafloor hydrothermal activity; Enceladus, whose subsurface ocean has confirmed hydrothermal vents (Hsiang-Wen Hsu et al., 2015) and where the Cassini mission detected molecular hydrogen consistent with ongoing serpentinization; Titan, whose hydrocarbon chemistry runs on different couples but still under sustained disequilibrium. Where the chemoautotrophic conditions hold, the framework favors life, the origin step at the abductive register of [§7.8.4](<7.8.4 What is Confirmed.md>) and its subsequent elaboration more strongly, with the timescale to emergence set by local chemistry. Whether biosignatures are detectable from current and near-future missions is an empirical question; the framework's answer is that the conditions for which we are looking are the ones the framework has already specified.

*Viruses and the boundary of life.* Viruses are the hardest boundary case in biology, and this account locates the boundary precisely. A virus has heritable genetic information and evolves by natural selection: it satisfies the Darwinian component of the NASA definition. But it has no self-producing recursion of its own. Outside a host cell, a virus does nothing: no metabolism, no energy throughput, no self-maintenance. It is structured information encoded in Substance, capable of being read by another organism's closure machinery and causing that machinery to produce copies of the virus. The production is real; what is absent is any closure that belongs to the virus itself. The virus recruits another organism's self-production without having self-production.

This is why the question of whether viruses are alive is not a question about parasitism. Parasitic organisms (tapeworms, ticks, parasitic plants) are fully alive: they have their own self-producing recursions, they metabolize, they maintain themselves, they have an inside. What makes them parasitic is that they draw their energy from a host rather than directly from the environment. The closure is present; only the energy source is borrowed. Viruses are different in kind, not degree. They lack closure entirely. On the present account, a virus is structurally closer to a crystal or a prion (a pattern in Substance that causes its own replication under the right conditions) than to even the simplest living cell. The line is drawn not at complexity, not at cell membranes, not at the presence of DNA, but at whether a self-producing recursion is present at all.

*Synthetic biology and what counts as alive.* The account also bears on synthetic biology and the question of whether non-natural systems can count as alive. The criterion is structural: closure plus sustained energy throughput. A computer simulation that runs a model of a self-maintaining cell is not alive: the simulation is a model, not a closure. A wet-chemistry artificial cell that genuinely closes its production cycle and dissipates energy through itself is alive, regardless of how it was assembled. The line is drawn at structural function, not biological history. This is consistent with the NASA definition's process-rather-than-substrate orientation while clarifying what the process consists in.

The site of the first closure on Earth (alkaline hydrothermal vent, surface pond with wet-dry cycling, mineral-surface catalysis, or other redox-disequilibrium environment) is empirically open. The framework commits structurally to the *kind* of conditions required (sustained chemical disequilibrium without pre-evolved molecular machinery) and abductively favors chemoautotrophic-vent scenarios, but does not commit to the specific site.

The genealogical question, single origin and shared ancestry (LUCA or a LUCA-like community) versus many independent origins under ecological incumbency lock-in, is empirically open. The structural-identity claim does not depend on its resolution, but resolving it remains a live target for paleobiology, comparative genomics, and the search for any surviving shadow biosphere lineages (Paul C. W. Davies, 2011).

Whether life elsewhere shares Earth's chemistry or only its structural identity is the central astrobiological question. The framework predicts the configuration (closure plus sustained energy throughput plus heritable specification) and the *kind* of site at which the first closure is favored, not the chemistry that realizes it. Whether biosignatures are detectable at the targeted candidate sites, Mars's early wet period, Europa, Enceladus, Titan, and the broader exoplanet population, is open for current and near-future missions.

Whether the cosmic-evolutionary trajectory's apparent directionality toward cognitive depth is robust across cycles, contingent on auxiliary premises (sustained ecological complexity, social-coevolutionary depth, niche pressure for recursive self-modeling), or an artifact of a single observed instance is the deepest open empirical question the framework leaves; cephalopod–vertebrate convergence makes the question tractable but does not by itself settle the cross-cycle generality.

And the boundary between marginal cases (viruses, prions, complex computer simulations, sufficiently sophisticated synthetic-biology constructs) and genuine instances of life is sharpened by the closure-plus-throughput criterion but admits practical adjudication only case by case as new candidates arise.

*Forward handoff to Chapter 8.* The outside account of life ends at the closure-plus-throughput configuration as observed from without. What that configuration is like *from within* (what subjective experience consists in once a self-modeling recursion is deep enough) is the chapter-end Chapter 7 → Chapter 8 lift this cluster carries on behalf of the chapter. [§8.1](<8.1 Drive.md>) reads consciousness from inside, recovering awareness as the interior aspect of the living recursion once the structural ground established in §[§7.1](<7.1 Convergence of Method.md>)–7.8 is in place. The dialectical engagement with the standard rival accounts of mind (the hard problem and the conceivability arguments, Russellian monism, idealism, eliminativism and illusionism, and cosmopsychism) is the work of the [§4.3](<4.3 Physics and Mind.md>) cluster (§[§4.3.1](<4.3.1 The Hard Problem of Consciousness.md>)–4.3.5).


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← [7.8.4 What is Confirmed](<7.8.4 What is Confirmed.md>) | [7.9 Synthesis](<7.9 Synthesis.md>) →
