Concept Library
Concepts
97 focused articles on the ideas, terms, arguments, and thought experiments that make up the theory.
Browse below by theme, or visit the Topic Hubs for guided collections, the Reading Paths for curated sequences, or A–Z index for everything.
New here? Start with these three concepts to understand the core argument: Ixperiencitness (what makes your experience yours), Structure and Functioning (what produces consciousness), and Superimmortality (why you survive death).
Or take the guided path →Core Concept (31)
5 After Death Theories
The five existing answers humanity has proposed to the question of what happens at death: reincarnation, heaven and hell, death-as-illusion, death-as-final...
Core ConceptCitoixperiencitness
The ixperiencitness produced by a cidentireplica. It is your "you-ness" as experienced through a body that stays structurally identical to yours over time.
Core ConceptComboixperiencitness
The ixperiencitness produced by a body that mixes replica types. Most realistic cases of survival combine features of several types at once.
Core ConceptConscious survival
Survival defined from the inside. A future moment counts as your survival if you experience that moment as yours, regardless of which body produces it.
Core ConceptConsciousness
Your inner experience of being a particular body: what it is like to be you. The book treats consciousness as something brain structure produces, not as a...
Core ConceptCorixperiencitness
Your conscious experience as produced by a body sharing your core structural organization. The closest version of you-ness that another body type can produce.
Core ConceptEnhaimmortality
Immortality realized through enhanced versions of you. The bodies that produce your ixperiencitness in the future may be more capable than the one you started...
Core ConceptEnhaixperiencitness
The ixperiencitness produced by an enhanced replica. Your you-ness, but with augmented mental or physical capacity.
Core ConceptFitoixperiencitness
The ixperiencitness produced by a fragmented replica. Portions of your you-ness distributed across other bodies, such as children, students, or anyone you have...
Core ConceptIdoimmortality
Immortality through "ido" (identity-of-original) replicas. A specific class of bodies in the theory's full inventory.
Core ConceptIdoixperiencitness
The ixperiencitness produced by an ido-class replica. A body whose structural relationship to you preserves a particular identity property of the original.
Core ConceptImmortality
The condition of having no future point at which you cease to experience consciousness. The book argues this follows logically from the production premise. It...
Core ConceptInsixperiencitness
The ixperiencitness produced by an instantaneously formed replica. A body that comes into being already structured like you, with no causal chain to the...
Core ConceptIsoixperiencitness
The ixperiencitness produced by an iso-material replica. Your structure realized in different matter than the original: silicon, simulation, or alternative...
Core ConceptItoimmortality
Immortality through any body that produces your ixperiencitness. The broadest form of the theory's immortality claim.
Core ConceptIxperiencitness
The quality of subjective experience that makes it yours. Coined from "I experience it" plus the suffix "-ness." This is the central new word the theory...
Core ConceptLife after death
The continued occurrence of your ixperiencitness in some body, after the death of your current one. The book argues that once you accept how brain structure...
Core ConceptMusixperiencitness
Your conscious experience as produced by a body that reproduces your musical and auditory neural patterns. What it is like to be you, through the lens of sound...
Core ConceptNrgixperiencitness
The ixperiencitness produced by "nrg" (energy-based) replicas. Consciousness arising from an energy pattern rather than from ordinary matter.
Core ConceptOrixperiencitness
The ixperiencitness produced by an "ori" (original) body. The specific version of you that started this lifetime, before any copies.
Core ConceptPrinciples of superimmortalism
The principles that follow once you accept superimmortality: how it changes ethics, identity, and the way to live.
Core ConceptPrinciples of superimmortality
The core principles of the theory itself: production, substrate independence, recurrence, and the conclusions they force about death and identity.
Core ConceptProductional itobody Immortality
Immortality made possible because some body that produces your ixperiencitness will be produced again. The active version of the recurrence claim.
Core ConceptScience of superimmortality
The scientific framework for studying superimmortality. Covers its premises, its predictions, the conditions under which it could be falsified, and what...
Core ConceptSimixperiencitness
The ixperiencitness produced by a simulated replica. A body whose structure is realized in a computational substrate rather than physical biology.
Core ConceptSuperimmortalism
The philosophical position that follows from accepting superimmortality. A worldview, a set of values, and a practical stance.
Core ConceptSuperimmortality
The theory's central claim: your ixperiencitness will be produced again and again by different physical systems across space and time. Stronger than ordinary...
Core ConceptTotal consciousness
The complete set of all conscious experiences across all bodies that produce your ixperiencitness. Not just one lifetime, but every one of them taken together.
Core ConceptTritoixperiencitness
The ixperiencitness produced by a truncated replica. A body derived from your structure but with portions removed.
Core ConceptTypes of life after death
The different forms life-after-death can take under the theory: continuation in a replica, fragmentation across many, enhancement beyond your current...
Core ConceptVitoixperiencitness
The ixperiencitness produced by a "vito" replica. A body that shares your structure but has been allowed to drift naturally over time.
Replicas (10)
Cidentireplica
A continuing identical replica. A body that maintains structure and functioning identical to yours over time. Both bodies produce the same awarepath...
ReplicasComboidentireplica
A combination identical replica. A body that holds more than one replica property at once: continuing and enhanced, fragmented and simulated, and so on.
ReplicasEnhaidentireplica
An enhanced identical replica. A body that produces your ixperiencitness but with capabilities you do not have. Future, augmented versions of you.
ReplicasFidentireplica
A fragmented identical replica. A body that produces only part of your ixperiencitness. The book argues this is the most common form of you-ness persistence...
ReplicasIdentireplica
An identical replica. A body whose structure and functioning are identical to yours at a moment in time. The simplest case the theory examines.
ReplicasInsidentireplica
An instantaneously formed identical replica. A body created in its final state with no causal continuity to the original. Useful for testing whether causal...
ReplicasItoidentireplica
Any identical replica in the broad ito- category that produces your ixperiencitness through identical structure.
ReplicasMusidentireplica
A musical-structure identical replica. A body that reproduces the patterns of neural activity associated with musical cognition and auditory consciousness.
ReplicasNrgidentireplica
An energy-substrate identical replica. Your structure realized in an energy pattern rather than in ordinary matter.
ReplicasVidentireplica
A diverging identical replica. A body that begins identical to you but is allowed to drift naturally over time, becoming gradually different.
Paths (7)
Awarepath
The complete sequence of conscious experiences produced by a body over its lifetime. Your subjective life seen from the inside, treated as a single object.
PathsExpective Awarepath
An awarepath that someone is currently expecting or anticipating. The modeled version of a possible future conscious life.
PathsIxpepath
The path your ixperiencitness takes over time. Tracks how the you-ness produced by a body changes across its lifetime as the body itself changes.
PathsMentapath
The mental-process path of a body. The sequence of mental functions over time: the mental side of what produces an awarepath.
PathsPhysapath
The physical path of a body, restricted to the properties that actually produce consciousness. A subset of the fuller physipath.
PathsPhysipath
The complete physical path of a body. Every physical state it passes through, including states that do not contribute to consciousness.
PathsSensepath
The complete sequence of sensory stimulations that affect a body over its lifetime. What your senses delivered to you, from birth to now.
Continuums (20)
Awarecontinuum
The total grouping of all possible awarepaths. Every conscious lifetime that could exist, treated as a single mathematical object.
ContinuumsCitoawarecontinuum
The awarecontinuum restricted to continuing identical replicas. Only the lifetimes produced by that specific body type.
ContinuumsCitoixpecontinuum
The continuum of all ixperiencitness paths produced by continuing identical replicas. Tracks how your you-ness changes across that family of lifetimes.
ContinuumsContinuum structure
The general structural concept underlying every continuum in the theory: a connected sequence of states. Foundational for awarepath, physapath, fazspace, and...
ContinuumsCoriawarecontinuum
All possible conscious lifetimes produced by bodies that share your core structural organization. Maps the space of lives that are structurally yours at the...
ContinuumsCorixpecontinuum
How your subjective identity changes across bodies that share your core organization. Tracks your you-ness through the most structurally similar class of...
ContinuumsFazcontinuum
A connected set of phase-states that a body can pass through. Combines the fazspace coordinate system with the continuum-structure concept.
ContinuumsFazmulticontinuum
A multi-continuum of fazcontinuums. The structure you get when many fazcontinuums are grouped together.
ContinuumsFitoixpecontinuum
The continuum of ixperiencitness paths produced by fragmented replicas. How your you-ness can be distributed across many partial copies.
ContinuumsInsixpecontinuum
The continuum of ixperiencitness paths produced by instantaneously formed replicas.
ContinuumsIsoixpecontinuum
The continuum of ixperiencitness paths produced by iso-material replicas. Your you-ness across different physical substrates.
ContinuumsItoixpecontinuum
The continuum of ixperiencitness paths produced by all itobodies. The broadest grouping, covering every body that produces your you-ness.
ContinuumsMultifazcontinuum
The most general continuum in the theory. A multi-phase, multi-continuum structure that holds all possible conscious lives together. The mathematical setting...
ContinuumsMusixpecontinuum
How your subjective identity changes across bodies that reproduce your musical and auditory neural patterns. A specialized slice of the broader identity...
ContinuumsNrgixpecontinuum
How your identity changes across bodies made of energy patterns rather than ordinary matter. Tracks your you-ness through non-material substrates.
ContinuumsOriepicontinuum
The continuum of higher-level ("epi") properties produced by original bodies. The emergent structure of consciousness for the original you.
ContinuumsOrixpecontinuum
The continuum of ixperiencitness paths produced by original bodies. The path your you-ness takes through your one original lifetime.
ContinuumsSimixpecontinuum
How your identity changes across computationally simulated versions of you. Tracks your you-ness through digital and virtual substrates.
ContinuumsVitoixpecontinuum
The continuum of ixperiencitness paths produced by diverging replicas. Your you-ness as it drifts across vito-class bodies over time.
ContinuumsVitophysicontinuum
The continuum of physical paths taken by vito-class (diverging) replicas. The matter-side counterpart to the vitoixpecontinuum.
Arguments (9)
2=2 argument
Two identical things can be the same as concepts while different as objects. That gap is why consciousness, which is a pattern, can recur even though a...
ArgumentsAdjective argument
Consciousness behaves like an adjective, not a noun. It is a property of physical structures, not a separate substance. The argument draws out what follows for...
ArgumentsArguments for multiplicity
A set of reasons to believe that the same conscious "you" can exist in multiple bodies at once. Each follows from treating consciousness as a property of...
ArgumentsArguments for superimmortality grouped into types
An organized index of every argument the theory makes for superimmortality, sorted by type (existence, multiplicity, recurrence, structural) and by what each...
ArgumentsCosmic justice argument
A discussion of whether superimmortality, if true, is fair. The question turns out to be harder than it looks, once you stop treating one lifetime as the whole...
ArgumentsCourage and cowardice argument
An argument about the moral weight of taking superimmortality seriously. Refusing to follow the premises to their conclusion is its own kind of intellectual...
ArgumentsIxperiencitness arguments
The collected arguments for three claims: that ixperiencitness is real, that it is what personal survival consists in, and that it can be produced by more than...
ArgumentsOriarguments
Arguments about "originals" specifically: the first body you were born in, the one writing this sentence. These arguments show why the original has no stronger...
ArgumentsTest for originalness argument
If two bodies produce identical consciousness, no test could determine which is the "original". The argument uses that fact to show that originalness is not a...
Theories (2)
Scientific theory of immortality
The umbrella name for the theory presented in the book. A fully scientific account of why permanent death is incoherent for a conscious being.
TheoriesScientific theory of life after death
An older alternative name for the theory. It emphasizes that life-after-death is a scientific question, not a religious one.
Proofs (6)
Citoexistence proofs
Proofs and supporting evidence for the actual or potential existence of cidentireplicas: bodies that maintain identical structure to yours over time.
ProofsComboexistence proofs
Proofs that combinations of replica types are possible and meaningful. A single body can be enhanced and continuing and fragmented all at once.
ProofsExipermental and rational proofs
Two kinds of proof for the theory's claims. Experimental proofs describe what observation could show. Rational proofs describe what reasoning alone forces.
ProofsIsoexistence proofs
Proofs that iso-material replicas are physically possible: bodies that produce your ixperiencitness from different matter than the original.
ProofsItoexistence proofs
Proofs that itobodies of various kinds exist or can exist. The theory's case that bodies producing your ixperiencitness are real, not just hypothetical.
ProofsVitoexistence proofs
Proofs that diverging (vito-class) replicas are physically possible and have meaningful identity properties.
Spaces (3)
Fazspace
A coordinate system for consciousness. Every possible conscious state is a point. Every life is a path through that space. The theory's mathematical setting...
SpacesItofazspace
Fazspace restricted to itobodies. The coordinate system covering all bodies that produce your ixperiencitness.
SpacesItospace
The space of all possible itobodies. Every body that could produce your ixperiencitness, treated as a single mathematical object.
Other (8)
Awareconvergence
The process by which two previously different awarepaths become more similar over time. Two conscious lives that drift toward shared experience.
OtherAwaredivergence
The process by which two previously similar awarepaths become more different over time. Shared past, increasingly different futures.
OtherConscious multiplicity
The principle that the same ixperiencitness can be simultaneously produced by multiple physical systems. You are not limited to one body at one time.
OtherItobody
Any body that produces your ixperiencitness. An umbrella term covering every replica type, from the original you to enhanced future versions.
OtherItomultiplicity
The condition of multiple itobodies simultaneously producing your you-ness. Conscious multiplicity applied across the full taxonomy of replica types.
OtherIxperiencitness duplication
The phenomenon of one ixperiencitness being produced by more than one body. The theoretical possibility that conscious multiplicity rests on.
OtherStructure and functioning
The complete physical organization of a system (structure) together with its dynamic activity (functioning). The book's claim is that consciousness is produced...
OtherSupermortal
A being that dies many times in many bodies, and also lives again many times. The book's description of what every conscious being actually is in a universe...