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Work #1180 · Mature period

Past, Present and Future

Arthur N. Prior's 1967 systematic statement of tense logic — the modern logic of temporal language

Arthur Norman Prior · 1967 · English · Logic-philosophical treatise

Tradition: Analytic philosophy / Tense logic / Philosophy of time

Prior's 1967 systematic statement — tense logic, the modern logic of temporal language

Past, Present and Future (1967) is Arthur N. Prior's systematic statement of tense logic — the modal-logical apparatus he had been developing since 1954 for the formal-logical treatment of temporal language. The book develops: the basic past-tense and future-tense operators (P, F); the metric tense logics; the branching-time logics for the open future; the Stoic and Megaric ancestry; the proper relation to the philosophy of time. Founding text of modern tense logic and a major work of analytic philosophy of time.

Author

Editions cited

  • Past, Present and Future (Oxford UP, 1967)
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School Embodiments

Analytic Metaphysics / Logical Atomism · 25%
Logicism · 20%
Presentism · 15%
Historicism · 10%
Aristotelianism · 5%
Realism · 10%
Analytic Metaphysics / Logical Atomism 25%

Foundational systematic text of analytic-philosophical tense logic.

"Tense logic — the modal-logical apparatus for temporal language — is the proper analytic-philosophical framework for the philosophy of time." (Past, Present and Future)
Logicism 20%

Major contribution to modal logic — the technical-formal apparatus developed at length.

"The formal-modal apparatus — P for past, F for future, G for 'always will be,' H for 'always has been' — admits of various interesting systems each with its own axiomatic structure." (Past, Present and Future)
Presentism 15%

Prior is the major modern-analytical defender of presentism — only the present is real, past and future are not.

"What is past is no longer; what is future is not yet; only the present is real. Tense logic must respect this presentist position." (Past, Present and Future)
Historicism 10%

Strong historicist-philosophical sensibility — Stoic and Megaric ancestors of modern tense logic recovered.

"What the Stoics — Diodorus Cronus, Chrysippus — developed about modal-temporal-logical relations the modern tradition has rediscovered." (Past, Present and Future)
Aristotelianism 5%

Engagement with Aristotle's De Interpretatione 9 on future contingents.

"Aristotle's sea-battle argument is the locus classicus of the philosophical problem; tense logic provides the modern formal framework." (Past, Present and Future)
Realism 10%

Realist about temporal-modal facts — though the realism takes presentist form.

"The proper realism about time is presentist realism — what is, now, is real; what was, was real then; what will be will be real when it happens." (Past, Present and Future)

Internal Tensions

Prior's tense logic has become a flourishing research programme; the presentist commitments have been variously assessed across the philosophy of time.

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I. Time

The 1967 mature-Prior moment of systematic tense-logical statement.

Attributes
Extent: Infinite Ontological Status: Substantival Grain: Continuous Freedom: Non-Deterministic Traversability: Linear Direction: Uni-directional Dimensionality: One
✦

II. Space

The Manchester-Oxford analytic-philosophical setting.

Attributes
Extent: Infinite Ontological Status: Substantival Curvature: Flat Dimensionality: Three Locality: Local
◉

III. Matter

The formal-logical apparatus the treatise develops.

Attributes
Extent: Infinite Ontological Status: Substantival Conservation: Conserved Dimensionality: Three Locality: Local
◎

IV. Observer

The presentist subject as proper observer of temporal-tense-logical structure.

Attributes
Time Instance: Single Space Instance: Single Knowledge Extent: Partial Knowledge Retainment: Total Physicality: Embodied Agency: Active Number: Plural Metaphysical Agency: None
⚡

V. Energy

The intellectual energies of the systematic-logical-philosophical work.

Attributes
Extent: Infinite Ontological Status: Substantival Conservation: Conserved Dispersibility: Irreversible
⧉

VI. Information

The systematic content of tense logic.

Attributes
Ontological Status: Substantival Cosmic Conservation: Conserved Personal Conservation: Conserved Granularity: Discrete

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.

94%
Titus Lucretius Carus
32/34
93%
Epicurus
28/30
91%
Gottlob Frege
31/34
90%
Plutarch
27/30
88%
Brigham Young
30/34
88%
Derek Parfit
30/34

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.

73%
LDS / Latter-day Saint Theology
23/26
71%
Thomism
23/26
71%
Transcendental Thomism
23/26
71%
Anti-Trinitarianism
23/26
71%
Deontological Ethics
23/26
71%
Manichaeism
22/26
70%
Effective Altruism
22/26
70%
Cartesianism
21/26

How Past, Present and Future resolves each dilemma

48 resolved positions across 4 dimensions, including 6 distinctive where the majority of schools go the other way · 9 unaligned.

Each dimension is sorted so minority positions come first. Mainstream positions are folded into an expandable list.

Time · 9 dilemmas · 3 distinctive

Persistence, the future, and the direction of becoming.

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%)
Distinctive · only 15% of schools agree (31/202)
Could we owe future generations more than is materially possible to provide?
If we owe future people a habitable planet and the material means to flourish, and the cosmos is bounded in ways that make those obligations impossible at some scale, the obligation and the possibility come apart. Where they come apart turns on what kind of finitude we live in.
Both time and matter are unbounded; we cannot in principle owe more than is possible.
On this view, the cosmos has the resources to support whatever flourishing future generations are capable of, given sufficient time and intelligence. The impossibility concern is misplaced; the real questions are about trajectories and choices, not about resource ceilings.
Roads not taken Time is unbounded but matter is not; we can owe more across long time than the matter can provide. (47%) · The owing-and-possibility question is level-dependent; we owe what is appropriate at the level we act on. (26%) · The cosmos is bounded; our obligations to future generations are bounded with it. (12%)
6 mainstream positions
Do you really choose? The future is open and you are a genuine origin of it. 69% Are addicts responsible for their addiction? The addict could have chosen otherwise — that's why recovery is real. 69% Should we hold AI systems responsible for what they do? An AI without a free will is not the kind of thing that can be responsible. 69% 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, all mainstream
Is the world created from nothing? Yes — matter was created and is conserved as a real substance. 55% Is the physical world fully real? Yes — the physical world is fully real, mind-independent, persisting. 55% Does matter have intrinsic moral standing? Matter is morally considerable insofar as it is created or conserved good. 55% What is money? Money is a real institution with intrinsic features. 54% What is a nation? A nation is a real moral community with intrinsic character. 54% What makes someone male or female? Sex is a real biological kind with given content. 54% Should we edit the human germline? Human nature is a real biological kind given by reproductive biology or by creation; editing the germline transgresses what is given. 54%

Observer · 37 dilemmas · 3 distinctive

Mind, agency, and the knower's relation to the known.

Distinctive · only 13% of schools agree (27/202)
Is reality fundamentally digital?
Pancomputationalism, Planck-scale quanta, simulation theory and Kabbalistic letter-mysticism all say yes — but for very different reasons. The rest of the atlas says no.
Yes — bits, quanta, computational substrate.
On this view, the world is at bottom discrete and law-governed, with no metaphysical agency above or behind the substrate. Reality reduces to bits or their physical analogues; the continuous appearance of fields and flows is coarse-graining over discrete underlying structure.
Roads not taken No — continuous divine sustaining act, the Tao that knows no joints, the One's self-disclosure. (44%) · No — continuous fields, classical limits, analog deep structure. (37%) · Yes — but divinely-discrete: divine letters, momentary cognitions, atomistic theism. (6%)
Distinctive · only 13% of schools agree (27/202)
Are there indivisible units of experience?
Whiteheadian actual occasions, Buddhist moments of mind, Kabbalistic letter-cognitions, IIT phi-units — or the unbroken Jamesian stream? The atomism of experience cuts across naturalism and theism alike.
Yes — naturalist quanta of experience.
On this view, experience comes in discrete units defined by the substrate: information-theoretic phi-units, computational frames, discrete neural events. There is no further metaphysical agency that knits them; the appearance of a stream is the way many discrete events present to introspection.
Roads not taken No — continuous divine presence; consciousness is the unbroken witness. (44%) · No — continuous Jamesian stream, phenomenological lived time. (37%) · Yes, theistic atomism — actual occasions, divine letters, momentary cognitions. (6%)
Distinctive · only 13% of schools agree (27/202)
Is memory stored or reconstructed?
Engrams and traces — or continuous re-narration each time you remember? The cognitive-science debate has a theological cousin: divine memory holding each hair, or the ancestors' continuous remembering.
Stored — discrete engrams, traces, weights.
On this view, memory is the readout of discrete information stored in the substrate: engrams, synaptic weights, file-like records. Reconstruction at retrieval is real but secondary; without the stored bits there would be nothing to reconstruct from.
Roads not taken Held in continuous divine or ancestral remembering — neither stored discretely nor purely reconstructed. (44%) · Reconstructed — continuous re-narrating, no fixed engrams. (37%) · Stored — in divine memory's discrete particulars, or in karmic-record units. (6%)
25 mainstream positions
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% Is environmental damage ever truly permanent? Damage is real and permanent on the relevant timescales. There is no recovery; there is only limitation. 66% Can a civilization recover from collapse? Civilizational complexity is hard to build and easy to lose; recovery is at best partial. 66% Does the second law of thermodynamics mean something morally? Entropy is what time is. The moral weight, if any, is the weight of working against the current. 66% When does a person begin? A person exists from conception — when a new being comes into existence. 54% What is marriage? Marriage has a given form — it’s a kind of thing we recognize, not make. 54% Does environmental harm in another country bind me morally? Moral obligation tracks the relations one is in; distance does matter, structurally. 50% Can prayer for someone far away affect them? Prayer changes the pray-er, not the prayed-for. 49% Are coincidences ever more than coincidence? Coincidence is exactly what the math says it is. The pattern is in the noticer. 49% What is our place in nature? Active in a real nature — we cultivate, steward, transform. 48% Should we colonize space? Cultivating worlds beyond Earth is the next form of stewardship. 48% Is genetic engineering of food stewardship or domination? Genetic modification is cultivation by other means. 48% Is divine omniscience compatible with human freedom? The observer is in time; foreknowledge across times raises real freedom problems. 46% Does meditation reveal something genuinely timeless? Meditators are bounded observers reporting unusual brain states; the 'timeless' is metaphorical. 46% Does prayer change God's mind? If there is an addressee at all, it is in time; prayer is communication, and may genuinely change what comes next. 46% Are the dead morally present to the living? Observers are bounded by their own moment, and no further agency makes the dead present. 44% Do animals have moral standing comparable to humans? Animal minds are real because biology is the substrate of mind. 32% Could a fetal brain organoid in a petri dish be conscious? Brain tissue can in principle do what brains do; the question is integration. 32% 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% What happens to "you" when you die? Death is genuinely the end. 30% Could an AI have a mind that matters? No — mind is what a biological brain does, and an LLM has no brain. 30%
9 unaligned
Does history have a direction or meaning? Schools split: 37% / 23% / 19% — How is knowledge of reality produced? Schools split: 25% / 17% / 13% — If a teleporter copied and destroyed you, would you have survived? Schools split: 36% / 29% / 14% — Is salvation, liberation, or fulfillment individual or communal? Schools split: 15% / 14% / 4% — Is the late-stage dementia patient still the person their spouse married? Schools split: 36% / 29% / 14% — 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% — What makes someone the same person over time? Schools split: 36% / 29% / 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%
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