Work #1450 · Early period
Quantum theory, the Church-Turing principle and the universal quantum computer
Deutsch's 1985 founding paper of quantum computation
David Deutsch
· 1985
· English
· Scientific paper
Tradition: Quantum computation / philosophy of physics
Deutsch's 1985 founding paper of quantum computation
Deutsch's 1985 Proc. Royal Society paper articulating the universal quantum computer and quantum Church-Turing principle — founding paper of quantum computation, formally establishing the equivalence between quantum-mechanical computation and a universal abstract machine.
Author
Editions cited
- Proceedings of the Royal Society A 400 (1818): 97-117 (1985)
School Embodiments
Quantum Realism
35%
Founding quantum-computation paper.
"Universal quantum computer." (Quantum theory and Church-Turing)
Naturalism
15%
Major philosophy-of-quantum-computation paper.
"Philosophy of quantum computation." (Quantum theory and Church-Turing)
Logicism
15%
Foundational philosophy-of-computing paper.
"Foundational quantum-computational framework." (Quantum theory and Church-Turing)
Many-worlds-interpretation-influenced computational framework.
"Many-worlds-influenced computational framework." (Quantum theory and Church-Turing)
Analytic-philosophical tradition.
Internal Tensions
Quantum Church-Turing paper founded quantum computation.
⧖
I. Time
1985.
Attributes
Extent: Infinite
Ontological Status: Substantival
Grain: Discrete
Freedom: Non-Deterministic
Traversability: Linear
Direction: Uni-directional
Dimensionality: One
✦
II. Space
Oxford-quantum-foundations context.
Attributes
Extent: Infinite
Ontological Status: Relational
Curvature: Flat
Dimensionality: Three
Locality: Non-Local
◉
III. Matter
Quantum-computational paper.
Attributes
Extent: Infinite
Ontological Status: Relational
Conservation: Conserved
Dimensionality: Three
Locality: Non-Local
◎
IV. Observer
Early Deutsch.
Attributes
Time Instance: Multiple
Space Instance: Multiple
Knowledge Extent: Partial
Knowledge Retainment: Total
Physicality: Embodied
Agency: Passive
Number: Plural
Metaphysical Agency: Impersonal
⚡
V. Energy
Quantum-computational energies.
Attributes
Extent: Infinite
Ontological Status: Relational
Conservation: Conserved
Dispersibility: Reversible
⧉
VI. Information
Founding QC paper.
Attributes
Ontological Status: Substantival
Cosmic Conservation: Conserved
Personal Conservation: Conserved
Granularity: Discrete
Personas that cite this work
Personas with the nearest attribute fingerprint
Historical figures whose own classification on the same six-dimensional grid lands closest to this work's. Computed by attribute-agreement on coordinates both address.
Computed school proximity
The work's attribute fingerprint scored against all schools using the same quiz scorer. Useful as a sanity check on the hand-curated embodiments above.
How Quantum theory, the Church-Turing principle and the universal quantum computer resolves each dilemma
45 resolved positions across 4 dimensions, including 29 distinctive where the majority of schools go the other way · 12 unaligned.
Each dimension is sorted so minority positions come first. Mainstream positions are folded into an expandable list.
Time · 9 dilemmas · 5 distinctive
Persistence, the future, and the direction of becoming.
Distinctive · only 6% of schools agree
(12/202)
Do you really choose?
If the brain is a physical system and physical systems are governed by laws, then every choice is also a chain of causes — which raises the question of what was really left to choose.
Even if the universe is undetermined, you are not the chooser.
On this view, the indeterminacy of the universe — whether from quantum mechanics, sheer contingency, or something else — does nothing to recover meaningful choice. A coin-flipping brain is not a deliberating brain; randomness in the underlying physics doesn't translate into power for the observer. …
Roads not taken
The future is open and you are a genuine origin of it. (69%) ·
Choice is structural illusion — every event is fixed by the prior state. (10%) ·
Choice is real within a determined order — agency and determinism aren’t opposites. (9%)
Distinctive · only 6% of schools agree
(12/202)
Are addicts responsible for their addiction?
Addiction looks from one angle like the textbook case of agency failing — a person doing what they don't, in any meaningful sense, want to do. From another angle it looks like agency at work in hard conditions. Which it is depends on what agency is.
Even if the universe is undetermined, the addict isn't the chooser.
On this view, the indeterminacy of the universe does nothing to convert an addict's brain into a responsible chooser. Randomness is not freedom. The addict is being acted on by neurochemistry, by environment, by craving; the appearance of agency is downstream of these. Compassion is …
Roads not taken
The addict could have chosen otherwise — that's why recovery is real. (69%) ·
The addict's behaviour is the outcome of causes; 'responsibility' is a useful fiction, not a metaphysical fact. (10%) ·
The addict is genuinely responsible within a determined order. (9%)
Distinctive · only 6% of schools agree
(12/202)
Should we hold AI systems responsible for what they do?
When an autonomous AI takes an action that harms someone, the question of who or what is responsible — the developer, the operator, the model itself — turns on whether the model is the kind of thing that can be a responsible agent.
Neither AIs nor anyone else are the locus of free agency; the question is the wrong one.
On this view, the same reasons that undermine ordinary claims of human agency apply with equal force to AI. The brain is a coin-flipping organ; the model is a function on inputs. Neither is the kind of thing that can be the source of action …
Roads not taken
An AI without a free will is not the kind of thing that can be responsible. (69%) ·
An AI's behaviour is fully determined by training and input; 'responsibility' applies if at all to its makers. (10%) ·
The AI can be a genuine agent within determined conditions — and therefore genuinely responsible. (9%)
Distinctive · only 15% of schools agree
(31/202)
Is the universe running out of usable energy?
The heat death of the universe — entropy maxed out, no further work possible — is among the more sobering implications of mainstream physics. Whether it is structurally inescapable depends on what kind of finitude the cosmos has.
Both time and matter are unbounded; 'running out' is misframed.
On this view, the cosmos has neither a temporal horizon nor a material exhaustion point. The framing of running out presupposes bounds that the cosmos doesn't have. Energy gradients perpetuate; new configurations emerge; the categories that make heat-death scary don't apply at the cosmic scale.
Roads not taken
Time is unbounded but matter is finite; usable energy can fail without time failing. (47%) ·
Time both has and lacks bounds depending on the level you ask at; finitude is conventional. (26%) ·
The cosmos has bounds; heat death is a real horizon. (12%)
Distinctive · only 15% of schools agree
(31/202)
Are natural resources fundamentally finite, or only practically so?
Whether we can grow our way out of resource constraints — or whether the cosmos sets limits the economy ultimately must obey — depends on what kind of finitude matter has.
Resources are practically inexhaustible on cosmic scales; terrestrial limits are engineering.
On this view, matter and time are both unbounded at the largest scales. Terrestrial resource limits are real engineering and political constraints but not metaphysical ones; the cosmos can in principle support whatever expansion intelligence is capable of.
Roads not taken
Time goes on but matter is bounded; we are eventually constrained even with infinite time. (47%) ·
The finitude question is level-dependent; resource ethics happens at the level that constrains us. (26%) ·
Resources are finite in the strict sense; living well requires accepting the limit. (12%)
4 mainstream positions
Could we owe future generations more than is materially possible to provide?
Both time and matter are unbounded; we cannot in principle owe more than is possible.
15%
How much weight do future people deserve?
Future people are as real as you are — and their interests count for as much.
47%
Is regret rational?
The past is as real as the present; regret is a real attitude toward a real thing.
47%
Do we owe extinct species something we cannot give them?
Extinct species are as real as we are; they have standing.
47%
Matter · 7 dilemmas · 5 distinctive
What stuff is — fundamental, relational, or appearance.
Distinctive · only 15% of schools agree
(30/202)
What is money?
The question of what money is — a measured store of real value, an agreed-on practice, a relational ledger of debts, or just a name we apply to many different things — sits behind every argument about inflation, cryptocurrency, debt, and the state.
Money is the ledger of obligations among real people.
On relational views, money is not a substance you have; it is a record of who owes whom what. Debts and credits are real because the relations they track are real — to kin, to community, to ancestors, to land. Money is the form this …
Roads not taken
Money is a real institution with intrinsic features. (54%) ·
Money is a social practice — its content is what we make it. (16%) ·
“Money” names a family of practices — the definition question is nominal. (8%)
Distinctive · only 15% of schools agree
(30/202)
What is a nation?
Whether a nation is a real moral community with intrinsic character, a constructed legal-political artifact, a web of kinship and shared history, an imagined community, or a conventional partition of a deeper unity — these are real ontological positions with sharply different political downstream.
A nation is the web of kinship, ancestry, and shared land that hosts a people.
On relational views, the nation is the relational fabric — extended kinship, ancestral inheritance, shared ecology, communal practice — that hosts a people across generations. Borders matter less than belonging; lineage and land carry the weight that political structures only ratify.
Roads not taken
A nation is a real moral community with intrinsic character. (54%) ·
A nation is a constructed polity — a project, not a discovery. (16%) ·
“Nation” names a family of practices imaginatively held together. (8%)
Distinctive · only 15% of schools agree
(30/202)
What makes someone male or female?
Whether sex is a real biological kind, a constructed social category, a relational identity, a label applied to varied phenomena, or a conventional distinction within a deeper unity is the ontological question the contemporary dispute about gender is mostly about.
Sex and gender are constituted by relations of recognition.
On relational views, identity is not a property a person has alone; it is constituted by the web of recognition the person sits in. What makes someone a man or a woman in any thick sense is the relations of kinship, community, ritual, and recognition …
Roads not taken
Sex is a real biological kind with given content. (54%) ·
Gender is constructed; what counts as male or female reflects practice. (16%) ·
“Male” and “female” are family-resemblance terms — no single essence. (8%)
Distinctive · only 15% of schools agree
(30/202)
Should we edit the human germline?
Whether human nature is a given biological kind, a constructed category, a relational achievement, a family-resemblance cluster, or a conventional distinction within deeper unity is the ontological question the policy debate over heritable gene editing is mostly about.
Personhood is constituted by relations of descent and kinship; germline editing reshapes the relational fabric.
On relational views, what makes someone a person is the web of kinship, ancestry, and community they sit in — not a property the body carries alone. Heritable editing intervenes in exactly this fabric: the lineage that ancestors handed on, the descent that descendants will …
Roads not taken
Human nature is a real biological kind given by reproductive biology or by creation; editing the germline transgresses what is given. (54%) ·
The categories we count as 'human' are emergent from practice; germline editing is a practice-revision like any other. (16%) ·
'Human nature' is a cluster term without a single essence; the editing question is empirical, not metaphysical. (8%)
Distinctive · only 16% of schools agree
(33/202)
Is the world created from nothing?
Creatio ex nihilo is one of the most distinctive Western-theological claims. Whether matter was created from nothing, eternally exists, or is sustained moment-by-moment turns on what kind of thing matter is.
Matter is constituted by relations; the question of 'from what?' presupposes substance.
On this view, matter is not a stuff but a patterning — the standing relations among things, ancestors, processes, and places. The creatio-ex-nihilo question doesn't quite arise, because the ontology has no slot for a free-standing substance to be created or eternal. What persists is …
Roads not taken
Yes — matter was created and is conserved as a real substance. (55%) ·
Matter is real but emerges from something deeper — neither bedrock nor created-from-nothing. (23%) ·
Matter arises and dissolves through cosmic rounds; neither created from nothing nor eternal. (4%)
Observer · 37 dilemmas · 5 distinctive
Mind, agency, and the knower's relation to the known.
Distinctive · only 5% of schools agree
(11/202)
Is environmental damage ever truly permanent?
Extinction is forever; soil erosion takes centuries to repair; the carbon we emit will warm the climate for millennia. But whether 'forever' or 'millennia' means what they say depends on what kind of process the universe is.
What appears irreversible is reversible by the right action.
On this view, the appearance of permanence is a function of limits we have not yet exceeded. Divine action, sufficiently advanced technology, intentional restoration practice can in principle reverse what now appears irreversible. The lost is not gone for good; it is gone for now.
Roads not taken
Damage is real and permanent on the relevant timescales. There is no recovery; there is only limitation. (66%) ·
Loss is part of cycles; what disappears returns in another form. (17%) ·
From the standpoint of the One, the categories of permanence and loss are conventional. (8%)
Distinctive · only 5% of schools agree
(11/202)
Can a civilization recover from collapse?
Rome fell; Maya cities emptied; Bronze Age trade networks collapsed in a single generation. Whether what was lost can be recovered — or whether collapse is structurally final — depends on what kind of process civilization is.
Civilization is the kind of order that can in principle be restored.
On this view, the order that constitutes civilization — information, practices, institutions, ethics — is not destroyed by collapse, only dispersed. Given the right work, by humans, divine action, or both, it can be reconstituted. The historical pattern of recovery and renewal is partial evidence; …
Roads not taken
Civilizational complexity is hard to build and easy to lose; recovery is at best partial. (66%) ·
Civilization rises and falls in cycles; recovery is structural to history. (17%) ·
From the One's vantage, civilizational categories are themselves conventional. (8%)
Distinctive · only 5% of schools agree
(11/202)
Does the second law of thermodynamics mean something morally?
The universe trends from order to disorder. Whether that physical pattern carries moral weight — making the preservation of order, beauty, complexity a kind of cosmic duty — depends on whether time has the kind of structure morality could lean on.
Apparent entropy is reversible in principle; the moral category is restoration.
On this view, the second law describes local pattern rather than cosmic destiny. What is broken can be repaired — by divine action, by human work, by energetic intervention. The moral weight of restoration is real and not borrowed from the physics. The cosmos is …
Roads not taken
Entropy is what time is. The moral weight, if any, is the weight of working against the current. (66%) ·
Local entropy increase is part of a cycle; the moral category is participation in the cycle. (17%) ·
From the One's vantage, the second law is itself a feature of the conventional, not the ultimate. (8%)
Distinctive · only 9% of schools agree
(18/202)
What makes someone the same person over time?
When dementia hollows out memory, when a coma resolves with no recall, when you imagine being uploaded — the question of whether the surviving person is still you turns on what kind of thing the 'you' was to begin with.
You span moments — identity is a pattern that need not be located at a single now.
On this view, the observer is not bound to a single present. Identity is something that exists across moments — as a pattern, an ancestral line, a trans-temporal structure. Uploading, in this picture, is not a metaphysical impossibility but an engineering question; ancestors are real …
Roads not taken
You are your body — continuity is bodily continuity. (36%) ·
You are a soul — what persists through change is the non-bodily aspect. (29%) ·
There was never a fixed self to either preserve or lose. (14%)
Distinctive · only 9% of schools agree
(18/202)
Is the late-stage dementia patient still the person their spouse married?
Loss of memory, of recognition, of the cognitive patterns that made the person — does this end the person, or merely the person you knew? The answer turns on what makes someone who they are.
The person is the pattern across moments — diminished pattern, diminished person.
On this view, the person is constituted by a pattern extending across moments — memory, narrative, characteristic ways of being. As dementia erodes the pattern, the person is correspondingly diminished. What remains is real but is less than what was; the marriage to the person …
Roads not taken
Same body, same person — even when the cognitive pattern has changed. (36%) ·
The soul persists; the cognitive change is the body's, not the person's. (29%) ·
There was no fixed person to lose; care is owed to whoever is here. (14%)
20 mainstream positions
If a teleporter copied and destroyed you, would you have survived?
You are the pattern; the pattern survives the substrate change. You arrive.
9%
Are the dead morally present to the living?
Observers span moments; the dead are present in a real (not merely metaphorical) way.
13%
Is divine omniscience compatible with human freedom?
An observer can occupy multiple times at once; foreknowledge is not foreordering.
13%
Does meditation reveal something genuinely timeless?
Meditation accesses a trans-temporal level the ordinary observer doesn't ordinarily reach.
13%
Does prayer change God's mind?
Prayer participates in a trans-temporal liturgy or communion; the question of 'changing the mind' misses the trans-temporal mode.
13%
When does a person begin?
Personhood is conferred by being-in-relation.
15%
What is marriage?
Marriage is constituted by the web of relations it creates.
15%
What is our place in nature?
Embedded in a web — partners with the more-than-human world.
15%
Should we colonize space?
Colonisation continues the work that ended the wisdom of seven-generation thinking.
15%
Is genetic engineering of food stewardship or domination?
Editing the genome cuts into the relational fabric; we should be very slow.
15%
What happens to "you" when you die?
You were always a pattern. The pattern propagates.
18%
Could causation work backwards?
Causation runs one way — the arrow of time is real and structural.
68%
Is the asymmetry between memory and anticipation a real feature of time, or just of us?
The asymmetry is real because time itself has a real direction.
68%
Is the arrow of time a real feature of the cosmos, or only of how we describe it?
The arrow is real and structural; the asymmetry isn't an artifact of description.
68%
Should we trust expert testimony when we can't verify it?
Trust expertise whose conclusions a competent mind can in principle reproduce.
32%
Is religious revelation a real source of knowledge?
Revelation is evaluable by reason — and not above it.
32%
Does an LLM 'know' the things it correctly produces?
An LLM can produce correct outputs but not reason to them; useful, not knowing.
32%
Could an AI have a mind that matters?
An AI’s standing is constituted by the relations it enters.
15%
Do animals have moral standing comparable to humans?
An animal's standing is constituted by its place in the relational fabric.
11%
Could a fetal brain organoid in a petri dish be conscious?
The organoid's standing is constituted by the relations of care around its production.
11%
12 unaligned
Are coincidences ever more than coincidence?
Schools split: 49% / 37% / 8%
—
Are there indivisible units of experience?
Schools split: 44% / 37% / 13%
—
Can prayer for someone far away affect them?
Schools split: 49% / 37% / 8%
—
Does environmental harm in another country bind me morally?
Schools split: 50% / 29% / 12%
—
Does history have a direction or meaning?
Schools split: 37% / 23% / 19%
—
How is knowledge of reality produced?
Schools split: 25% / 17% / 13%
—
Is memory stored or reconstructed?
Schools split: 44% / 37% / 13%
—
Is reality fundamentally digital?
Schools split: 44% / 37% / 13%
—
Is salvation, liberation, or fulfillment individual or communal?
Schools split: 15% / 14% / 4%
—
Is truth universal, tradition-bound, situated, or constructed?
Schools split: 65% / 16% / 10%
—
What kind of religious-theological authority does the tradition recognize?
Schools split: 44% / 16% / 14%
—
Who is the moral primary — the individual, the community, the cosmos, the class, or the species?
Schools split: 40% / 28% / 14%
—
Information · 4 dilemmas, all mainstream
Is anything truly lost when someone forgets?
Information is conserved — the personal pattern is held even when an individual mind loses it.
39%
Does deleting your data online destroy something real?
Information at the cosmic level isn't destroyed; deletion only obscures access.
39%
Could the dead, in principle, be brought back?
The information that constitutes a person is conserved; restoration is in principle possible.
39%
Is forgiveness ontologically possible?
The offense persists ontologically; forgiveness is real moral work, but it doesn't erase what was.
39%