The words

record — A distinction that has been made and persists. A footprint. A memory. This sentence.

distinction — A difference that can be read: this against not-this. Every reading is one.

Symmetry (S) — The first condition: two sides, related, distinguishable, of the same weight.

break (ε, B) — The second condition: the smallest difference between two sides that were otherwise the same. The grain of sand in the jar. It never settles.

Constraint (C) — The fourth condition: nothing can be everywhere at once. There is one finite rate, the same everywhere; in our universe, the speed of light.

Actualization State (AS) — The now, where the break is made, held and read. Also the whole of what the axiom produces, read as one; every place is a local reading of it.

axiom — 1:1 + 1×ε @ AS, in full 1:1 + 1×ε @ AS [+α | −α]: perfect symmetry, one smallest break, at the now. Not how the universe began; what it is, now.

α (alpha) — The rate of the flow around the break, out and back. The one number the structure takes from measurement.

regress — A chain of answers in which every answer is a new thing that needs explaining, so the question is never closed, only moved one step back.

brute fact — A fact said to have no reason behind it: the universe is just there. The chapter calls it “a shrug, not a closure”.

dissolution — One of the book’s three moves. It removes a question by showing its framing was wrong: the question assumed something the axiom does not produce. Once the framing is corrected, the question does not arise.

frame — What any description needs: a place for the saying to stand. A frame is itself structure, so nothing cannot be described without turning into something.

substance — The stuff at the bottom: the thing not made of anything else, which everything else is made of. Every classical answer to “what exists?” assumed there was one to find. The axiom does not produce one.

coupling — Two records meeting so that each is now a distinction for the other. Light on a retina. A molecule at a receptor. This word, and you reading it.

record-architecture — Records coupling in a stable pattern across time. A hand. A brain. A star. Not a new kind of thing: records, holding together.

bit — The smallest committed record of a two-way difference. One grain in one jar. One ε. Below it there is no record.

information — The record history. Not something a record carries, but what the record’s own difference-and-its-lasting amounts to, read as a history.

relation — A fact about how records sit together: which came first, which is made of which, which limits which. Relations are not added to records; they are what records, taken together, are.

Ø — The pre-state: perfect symmetry, before the break. In the book’s picture, the ocean every ship moves through and every wake returns to.

universal — What many things share, like the threeness of three apples, three stars and three beats. On the 420 Code’s reading: an invariant readable across many records under an operation.

invariant — A feature that holds across many particulars when an operation is applied to them. Threeness under counting. Roundness under rotation.

property — A universal that shows itself through a stable coupling or response between a thing and an operation that probes it. Redness is the coupling of a surface, light and an eye.

proposition — What a sentence says. A recordable constraint on how things stand at a place and time; true if the world matches it.

induction — Going from what has been to what will be. Under the axiom it is not a leap across a gap: it is reading, from a site, the constraints the four conditions impose, and projecting what the now permits next.

constant conjunction — Hume’s name for what he actually saw between cause and effect: two kinds of event regularly occurring together, one always first.

site — A place where a record is being written or read. Every site is a local reading of the one Actualization State, not a now of its own.

resolution — The grain at which a site reads. Each site reads a cross-section of the one now at the resolution it can reach; a law is read at the resolution of one kind of happening.

trajectory-space — The paths still open from a site, given what has happened so far. The set of couplings the axiom permits at any site; read at the site as the future.

law of nature — A constraint the four conditions impose on every record, read at the resolution of a specific phenomenon. Not an instruction the universe obeys: what we read when we examine what the structure does.

actualisation rate — The rate at which possibility commits to actuality at coupling sites: how often a possible distinction becomes a recorded one. α is this rate at the electromagnetic layer.

cause — A record written at one site that, through bounded propagation, alters the trajectory-space at another site.

propagation — A record travelling from one site to another at the rate C permits. Causation is propagation, read at the layer where one record changes another.

counterfactual — An “if” about what did not happen: “if A had been the case, B would have been”, where A is in fact not the case. The book grounds it in trajectory-space, not in other worlds.

continuum — An unbroken stretch that can be cut into positions and instants without end. Zeno’s paradoxes treat motion as crossing a finished one. The book: the continuum is the reading, not the running.

writing-edge — The now, read as the active edge where records are being written: the place where the four conditions are executing. Not a moment inside time; what produces time.

substrate — The domain on which the axiom operates: the pre-state every record is a configuration of, never a material lying under the records. Appears in RES-6.1.

Lorentz invariance — In relativity, the fact that every observer, however they move, measures the same C and agrees on the causal order of events that can reach each other. Appears in RES-6.3.

record-lineage — The history Record has preserved at a site: what has been held as one thing across the changes. Not the matter, and not the arrangement of any instant.

referent — What a phrase picks out. “The same ship” can pick out three: the pattern, the matter, or the use.

wake — The record of every change a persisting thing has gone through. In the book’s image, the ship is the pattern Record keeps, the wake is the change, and the ocean is what receives it all.

mind-body problem — The four-hundred-year question of how mind and body are related, if mind has no weight or place and the body does. It stands on the premise that they are two things.

hard problem of consciousness — Chalmers’s name (1995) for the question why any physical processing is accompanied by experience, rather than running in the dark; and, sharper, why this experience has this character.

relocate, relocation — Showing a question was real but asked from a position nobody can stand in. Moved to a position that exists, it becomes a different question, and that one can be worked.

outside reading — A coupling described from outside, by another coupling looking on: its behaviour. What physics, chemistry and neuroscience describe.

inside reading — The same coupling described from its own position, facing the way it faces: what it is registering, from where it sits. Every record has both readings.

self-registration — The threshold at which a coupling-architecture begins to read its own records: its outputs loop back as its inputs. What produces a narrator on top of an operator.

operator — The coupling as it executes: the record being written, now, where it is made. Your heartbeat. Your breath. It does not need the narrator to run.

narrator — The later record-making that records what the operator already did: the report, the model of the self, the story. It arrives after. One of the operator’s capacities, not the operator.

close, closure — Keeping the question as asked and supplying the ground the tradition lacked. The question was well posed; the answers lacked the ground.

self — The narrator’s model of its own record-architecture. The main character of the narrator’s story. Real as a record, not real as a substance.

loop (self-reading loop) — The architecture reads its own state, writes a record of the reading, reads that record and folds it into the next reading. Its continuity, carried across sleep by the operator, is personal identity.

window — A self-reading architecture: a local place where the one inside looks out. One person. One dog. (Ch. 6, p. 150; short edition, The words, p. 5; Glossary, window.) Ø Horizons Ch. 6 uses the word at a smaller size, for the systems of one body, one of which is the speaking window; “this body is a building inside that building” (Horizons short edition, S pp. 61–62).

floor — What everything else stands on. In the work: one reality, one now, one awareness, performed in the act, as the axiom is.

one awareness — The work’s name for one reality and one now, together with the one rate. Awareness is coupling, not consciousness; consciousness is one expression of awareness.

pole — The inside as a direction, not a part. Each window is an instance of the axiom executing; the inside-pole is the inward direction of the axiom itself, the direction from which any instance is read.

interior — What every window opens onto. One, not one per window. The structural unity of which self-aware windows are local expressions.

solipsist — One who holds the one-window view: only his own mind surely exists. To hold it he must add an axiom naming one privileged site.

projection — What Ø Horizons does in its first eleven chapters: it takes a structural term already derived and reads it in one phenomenon. Here, the operator and the narrator, read in sleep, dreams, flow and habit.

speaking window — The one window of a body’s building through which its self-report comes. The narrator. The building has many windows; only one speaks.

freedom under constraint — Freedom as the capacity to commit within a field of constraint. Not absence of constraint, not chance; the third position the free will and determinism binary could not name.

responsibility — What “you coupled” entails, downstream. Not a further fact added when some condition is met; it attaches at the operator because the operator is what coupled.

gradient — What the four conditions produce at a coupling site: given the record, one path is computed as optimal, the lowest in cost. What determinism describes.

override — The capacity of an operator to act against what its gradient computes. What makes choice distinguishable from compulsion.

compulsion — The collapse of override under a narrowed corridor. Structural, not moral.

corridor — The range of states a body can keep running in. It has a width. Illness narrows it. Care widens it. When it narrows enough, override collapses; recovery widens it again.

geometry — The shape of what a coupling can do from where it is: which paths are available, and what each would produce.

raw geometry — What physics and habit alone would produce: what the coupling would do without its picture of itself. The “is” the tradition named.

full geometry — The raw geometry plus everything else the coupling is reading: its commitments, its whole-body state, and the fact that the inside is shared. Read correctly, it is the “ought” the tradition named.

compassion — The strongest weighting of correctly read geometry between self-aware windows. What self-preservation favours once the shared inside is in the reading. The ethical floor.

love — Committing to a particular window, at a particular cost, beyond what the correctly read geometry alone would choose. Above the floor.

structural consequentialism — The ethical measure as what an act actually writes into others and into the joint structure. Not pleasure, preference or utility, and not chosen from outside: the third condition supplies it.

joint viable set — The space of futures open to coupled windows together, given what their coupling has written so far. What the ethical measure tracks.

cooperative — Of an act: it opens more futures for the coupled windows together than it consumed. It widens the joint viable set.

parasitic — Of an act: it narrows the joint viable set beyond what the situation requires. Taking when sharing was available, harming when the resource was not used up. The book’s structural account of cruelty.

dynamic kinetic stability — Lasting by being rebuilt faster than you decay, with the rebuilding guided by records the living thing keeps. Dynamic, because it needs constant activity; kinetic, because it depends on rates, not energies.

persistence-inversion threshold — The crossing from chemistry to biology. Before it, things last by resisting the break; after it, by using their own records to rebuild themselves.

autocatalytic loop — A cycle of reactions whose products speed up its own reactions, so the loop makes its own catalysts. On its own it is not life; fire is one.

selection — What happens once a self-copying lineage varies: some variants last longer under decay and copy more. It needs variation, inheritance and differential continuation, and then it is not optional.

architecture — Any built thing that couples: a dog, a newborn, a network system, a person. The book’s full term is coupling-architecture.

valenced self-state — States an architecture registers as better or worse for its own continuation: its own welfare. Pain, fear, relief, curiosity, attachment are the biological examples.

precaution — Where an architecture may have valenced state and restraint costs little, the obligation runs as if it does, until it is better understood.

cruelty — Parasitic contraction of a valenced self-registering architecture’s viable set by another architecture acting with override. Not a sentimental category.

narrator depth — How deep and how broad an architecture’s reporting on itself runs. Two axes: recursion (modelling its own state, its own modelling, another’s model of it) and breadth (how many states, over what time, how faithfully).

coupling state — The state of an architecture’s own coupling: pain, hunger, threat, comfort; whether its corridor is widening or narrowing. Registering it is the criterion for obligation.

nociception — A reflexive damage-response. It is not yet pain: pain needs the damage folded into the corridor so it changes what the architecture does next.

coupling capacity — What a window can hold of the interior: the range of states it can register and the range of paths it can choose among under new conditions.

parasitic by omission — Refusing to help where help is available without overriding competing obligations. The failure is not inability; it is available refusal.

node — A point in a joint structure that other windows’ pathways run through. When someone dies, the joint structure is short one node.

grief — The survivor’s architecture registering that a node it had been routing through is no longer there. Grounded in the real narrowing of the survivor’s futures.

personal I — “I” naming the window: this body, this memory, this loop, this view. It closes at death.

structural I — “I” naming the interior the window opens onto. It does not close when a window closes.

defragmentation — At the scale of a person: the records a life wrote spreading, then dispersing into the whole until they are no longer traceable to that one window. Not vanishing. Dispersing.

actualisation-cost — The cost of anything happening at all. A universe that makes some possibilities real closes others, and where a valenced architecture registers the closing, it is suffering.

theodicy — A defence of a good god in the face of suffering. The classical theodicies consoled by reframing suffering as part of a larger pattern; the chapter answers without one.

parasitic contraction — One operator’s coupling narrowing another’s joint viable set when other paths were open. Cruelty in the strict sense.

non-parasitic structural cost — Suffering no operator’s override could have prevented: an earthquake, a virus, ageing and disease, predation, accident. Not what anyone did wrong.

mixed damage — Structural cost made worse by parasitic action or institutional failure. The common case.

purpose — What a thing is for at its own scale. A hammer is for nails. Purpose is coupling in context.

significance — What a thing weighs in the larger structure that registers it. What changed because it happened.

grounding — What a thing is for absolutely: its place in the plan of everything. The axiom does not supply it.

orientation — The lean every coupling has toward some paths and away from others. Orientation is what purpose is.

registration — What coupling at sufficient resolution does: when the coupling is fine-grained enough, the structure of the thing shows up in the coupling itself. Installed in Ø Horizons, Chapter 1.

self-model — The narrator’s running model of the body itself: what kind of thing it is, where its edges are, what is inside and outside. An ongoing construction, not a description of pre-existing fact.

unitive — The kind of transcendent moment in which the boundary between self and world drops.

coupling architecture — What an operator is configured to couple with, what records it carries, what paths it can reach.

coherence — How far a structure’s parts are non-arbitrarily related at their joint resolution. Not subjective. Measurable in principle.

proportion — Relation between parts at scales the architecture can read across: parts non-arbitrarily related to the whole.

integration — What a coherent structure looks like when its parts can be read without overwhelming the whole.

octave — The two-to-one ratio. The lowest-complexity harmonic coupling: the same note at another register.

rhythm — What repeated, sustained or otherwise structured coupling events produce in time. Pulse is one form; phrase, breath, silence and recurrence are others.

arena — A bounded region within which couplings run. A game is a miniature coupling arena with arena-specific constraints, voluntary or play-signalled entry, and a reversible outcome-space.

protagonist — The node: the architecture whose trajectory a story tracks. A person, an animal, a community, an idea. The receiver maps onto it.

correspondence-truth — Whether the events a story tells happened.

structural-truth — Whether the geometry a story propagates is stabilising or destabilising when adopted: whether it widens or narrows the receiver’s corridor.

compression token — A word: a reusable handle that points to a record-pattern. It sets off the hearer’s own pre-built pattern; nothing is copied.

joint structure — The overlapping record-patterns speaker, hearer and community have built up through parallel coupling histories. Where meaning lives.

wavefunction — The mathematics quantum mechanics uses for a system before it is measured. It carries every outcome, each with a weight.

measurement problem — The question of what separates a measurement from any other interaction, and why the wavefunction resolves here and not there. Open since the 1920s.

decoherence — The dispersal of coherence into the environment through record-writing; the way the everyday world emerges from the quantum one. A thing’s own parts and surroundings observe it all the time.

forcing function — What coupling at sufficient capacity does: it forces non-optionality in the paths it couples with, committing one and closing the others. What observation is.

observer — Any coupling strong enough to force one outcome in what it couples with. Not a privileged kind of system and not a mind. Observer and observed are two positions in one coupling.

eschatology — The study of the end: when it comes, what happens then, what comes after.

topology — The study of shape: inside and outside, continuity and connection. It asks what shape a thing has, not when it ends.

grain — The faint bias in the odds that crosses from one cycle into the next after defragmentation. Not a surviving record. Not memory, soul or self. (Glossary, grain (cycle-grain); H11, pp. 394–395.)

pre-agency biosphere — Life that is alive, coupling and self-maintaining, but not yet running an integrated narrator. It may be the corridor through which thinking beings could later arise.

scaffold — The interpretation, ritual, doctrine and authority a tradition built around the sacred, attaching it to an authority outside the person. When it falls, the registration remains.

Architecture B — Decision-making through measured consequence, open to inspection and challenge, rather than through coalition (Architecture A). What falls out when the axiom is accepted.

boundary — The line between a life’s own sovereignty and consequences that spill onto others. Below it, the person is sovereign; above it, the structure runs.

register — The level of language a claim is made in. The same move can be made in the language of theology or in the language of structure. (Structural Glossary, p. 5: “register tells you which face of the work the term belongs to”; Ø Horizons Ch 12.) First met on the canon page.

commitment layer — Where freedom works: what you commit to, the path you take with your override intact. (Ø Dissolutions Ch 10, p. 275: “Freedom operates at the commitment layer”.) First met on the canon page.

propagation layer — Where significance works: what your acts carry into the larger structure around you. (Ø Dissolutions Ch 10, p. 275: “significance operates at the propagation layer”; short edition: “Significance is what a thing weighs in the larger structure that registers it.”) First met on the canon page.

record-pattern — A pattern of records that keeps its shape while the records in it change. The ship whose planks are all replaced is one. So is your body. (Ø Dissolutions Ch 5: “the ship is recognised as a record-pattern rather than a substance”; p. 129: “Your body is a record-pattern”.) First met on the canon page.

actualisation source — What makes motion actual, not just possible. The ancient answer to Zeno left it open; the book places it at the now. (Ø Resolutions Ch 6: “the missing actualisation source the ancient account left open”.) First met on the canon page.

anthropic answer — The answer that starts from us, the askers. If the universe did not allow us, we would not be here to ask.

materialism — The view that everything is matter, arranged. Mind is matter doing certain things.

idealism — The view that everything is appearance to a mind. Take the minds away and the world has nothing to stand on.

mathematical Platonism — The view that numbers, sets and shapes are the real things, in a realm of their own, and the physical world is a copy.

process metaphysics — The view that there are no things, only stable patterns in change. The world is a doing, not a thing done.

neutral monism — The view that the ground is neither mind nor matter, but something under both, with mind and matter as its two faces.

panpsychism — The view that every scrap of matter carries a flicker of experience, and minds are what happens when the flickers combine.

formalism — In mathematics: the view that mathematics is symbols moved by rules, about nothing.

logicism — In mathematics: the view that mathematics is logic in disguise.

intuitionism — In mathematics: the view that mathematics is built by the mind.

fictionalism — In mathematics: the view that numbers are useful fictions.

nominalism — The view that only particular things exist. A universal is just the name we give to things that resemble each other.

conceptualism — The view that universals are in the mind, as ideas formed by meeting things.

family resemblance — A likeness made of overlapping likenesses, with no single feature shared by all. The many things called games share a family resemblance.

qualia — The felt qualities of experience: the redness of red, the hurt of pain. What it is like, from inside.

spacetime — Space and time taken together as one whole, as relativity reads them.

conserved quantity — A quantity whose total stays the same over time, as energy does.

regularity — In the question of laws: the view that a law of nature is a pattern that has been seen to hold, and nothing more.

necessitation — In the question of laws: the view that a law is more than a pattern. It is a relation of necessity: the second ball had to move.

best system — In the question of laws: the view that a law is whatever the best summary of all the facts includes.

constant conjunction — One kind of event always followed by another. On the old account, all we ever see of a cause.

INUS condition — A cause read as one needed part of a set of conditions that together are enough for the effect, where other sets could also bring it about.

possible worlds — Complete ways things could have been. Necessary means true in all of them, possible means true in some. A powerful tool of logic. Most people who use it do not think the worlds are real.

grue — A made-up colour word: green when seen before some future date, blue after. Every emerald seen so far has been grue, just as it has been green. It asks why we expect green tomorrow.

entrenchment — An old answer to the riddle: trust the words that have worked in predictions before, like “green”. It moves the question rather than answering it.

valid — Of an argument: its conclusion follows from its premises. If the premises are true, the conclusion must be.

paradox — An argument that feels valid and ends in a conclusion that is false.

actual infinity — A finished collection of infinitely many things.

potential infinity — Only the endless possibility of cutting further. Never a finished collection.

dualism — The view that there are two kinds of stuff, mind and matter.

interaction problem — Dualism’s puzzle: how two kinds of stuff that share nothing could act on each other. Also called the bridge problem.

illusionism — The view that there is no real felt character, only the system’s model of it.

combination problem — Panpsychism’s puzzle: how tiny experiences add up to one mind.

parallelism — The view that mind and matter are two separate processes that merely keep step.

emergence — Something new appearing at a level of complexity that was not there in the parts.

bundle theory — The view that a self is a bundle of passing perceptions, with nothing underneath that stays.

no-self — The Buddhist teaching, anatta, that what is called a self is a gathering of changing parts with no lasting ground.

fission — The thought experiment in which one person divides into two, each continuous with the first. Which one is you?

argument from analogy — Reasoning to other minds from your own: other bodies act as yours does, so they must have an inside as yours does. An argument from one case.

Mary's Room — A thought experiment. A scientist who knows every physical fact about colour sees red for the first time, and learns something.

stream of consciousness — The self as a running flow of experience: a process, not a fixed object.

mysticism — A claim to reach the deepest truths through special inner experience rather than through reasoning.

empirical — Known by observation and experiment, not by reasoning alone.

depersonalisation, derealisation — Conditions in which the self, or the world, keeps feeling unreal.

modal realism — The view that the possible worlds are real: complete universes, each as real as ours, cut off from each other.

determinism — The view that every event is fixed by what came before. Hard determinism adds: so there is no free will.

libertarian free will — The view that a free choice is fixed by nothing before it: you could have done otherwise, with everything else the same.

is and ought — The old gap between describing what is and saying what ought to be. No description, however complete, was thought to give an instruction.

naturalistic fallacy — The charge that “good” cannot be defined as any natural property. Define it as pleasant, and someone can always ask: but is that good?

duty ethics — Ethics as obligations that bind without condition. Do not lie. Keep promises.

virtue ethics — Ethics as being the right kind of person: honest, brave, just.

utilitarianism — Ethics as judging an act by what it produces: pleasure, preference or well-being, added up. Classical utilitarianism makes the total as large as it can.

care ethics — Ethics as attention to the particular other: the child, the patient, the vulnerable one across from you.

vitalism — The view that life needs a special force outside ordinary chemistry.

mechanism — In the question of life: the view that living things are physical systems organised a certain way.

biological naturalism — The view that a mind needs biological tissue, so a machine of silicon cannot have one.

absolutism — Holding a rule without any exception.

applied ethics — Ethics turned to particular questions of life: medicine, animals, machines, the planet.

the Epicureans — An ancient Greek school. On death: when we are, death is not, and when death is, we are not.

symmetry argument — We do not regret the time before we were born, so we should not regret the time after we die.

existentialism — The view that nothing is given, so you make meaning by choosing.

being toward death — The idea that knowing you will die is what gives a life its shape.

Hua-yen — A school of Buddhism in East Asia, from about the seventh century CE, which taught that every thing reflects every other.

theism — Belief in a god. Sceptical theism holds that the god’s reasons are beyond us.

evidential argument — An argument from suffering: some suffering serves no good at all, so a good, all-powerful god is unlikely.

hiddenness argument — A good god would not leave unbelieving those who would believe if it showed itself. So why does it hide?

process theology — The view that the god is not all-powerful, and shares the suffering instead of imposing it.

karma — In Indian traditions: the weight of what you do, carried forward into what happens to you, in this life or another.

nihilism — The view that no meaning is present and none can be made.

collapse — In quantum physics: the jump, on measurement, from many possible outcomes to one.

theology — The study of God and of religious belief.

the absurd — The demand for meaning, set against a universe that does not answer.

pragmatism — Judging ideas by what they do in practice. On meaning, the pragmatists turned from the question to what to do now.

perennial philosophy — The view that one insight runs through all the major religious traditions.

contextualism — In the study of religious experience: the view that no experience comes pure. It is shaped from the start by language, training and expectation.

sublime — What stops you through a scale or a violence too big to read as coherent: mountains in storm, the cosmos.

disinterested pleasure — A pleasure that wants nothing from the thing.

cadence — The turn that closes a phrase of music.

low-entropy — Simple: little left over, quick to read.

private language — A language grounded only in inner sensation, that no one else could check. It was argued that none could exist: the speaker could never check that a word meant the same thing twice.

Copenhagen interpretation — The working view of quantum physics in which measurement is a basic event, taken as given. A large everyday apparatus meets a quantum system, and the collapse happens.

many worlds — The reading of quantum physics in which there is no collapse. Every outcome happens, each in its own branch, and the branches are real worlds.

hidden variables — The view that quantum randomness hides a process already settled underneath.

Bell's theorem — A proof from 1964, confirmed by experiment since: the hidden settings cannot belong to each particle on its own.

eternal recurrence — The idea that every event returns, again and again, in exactly the same form.

the Stoics — An ancient Greek and Roman school. On the end of things: the cosmos returns to fire and is born again.

yuga cycles — The Hindu teaching of vast cycles of cosmic time that return, the end of one the beginning of the next.

apocalyptic — Teaching that the world ends in a final act of God, with a new heaven and a new earth.

longtermism — The view that the future is so large it should dominate our moral thinking.

existential risk — A risk that could end everything.

cosmopolitan ethics — The view that everyone everywhere counts.

non-identity problem — Which people will exist depends on what we do now. So can we wrong someone whose very existence hangs on our choice?

the numinous — The holy met as wholly other: fearful and fascinating at once.

ground of being — God not as a being among others, but as being itself, the ground of all that is.

God or Nature — One ground, not a person outside the world: God and Nature as one.

participation problem — The old puzzle for universals placed in a realm of their own: how do the things here take part in them? First met on the canon page.

new riddle of induction — The puzzle that grue poses: past evidence fits green and grue equally. What makes one of them the right thing to expect? First met on the canon page.

projectible — Able to be carried forward rightly into tomorrow. Green is projectible. The riddle asks why grue is not. First met on the canon page.

A-series — Time read as a moving now: events running from future, to present, to past. First met on the canon page.

simultaneity — Two events happening at the same time. Since relativity, whether two distant events are simultaneous depends on how the one judging is moving. First met on the canon page.

deduction — Reasoning in which the conclusion must be true if the premises are. First met on the canon page.

pre-established harmony — A form of parallelism: mind and body set going in advance, like two clocks keeping perfect time, so they agree without touching. First met on the canon page.

compatibilism — The view that freedom and determinism can both be true: a free act is one that comes from your own will, with nothing outside forcing your hand. First met on the canon page.

dukkha — The Buddhist teaching, the first of the four noble truths, that suffering belongs to the conditions of conditioned existence. First met on the canon page.

catharsis — What tragedy does for its audience: the purging of pity and fear. First met on the canon page.

rebirth — The teaching that a self passes from one life, or one cycle, into another. First met on the canon page.

Logic — The branch of philosophy that asks what must be true and what follows from what. On this walk it starts with one sentence that cannot be denied without being confirmed.

Metaphysics — The branch that asks what there is, underneath everything, and what must be there for anything to be at all.

Ontology — The part of metaphysics that asks what exists, and what kinds of things there are.

Knowing (epistemology) — The branch that asks how we know anything, and how far knowing can reach. Epistemology is its Greek name: the study of knowledge.

Philosophy of science — Asks what laws of nature and causes are, and why science works at all.

Philosophy of mathematics — Asks what numbers and mathematical truths are, and why mathematics fits the world.

Change — The part of metaphysics that asks how anything moves, and how a thing stays itself while its parts change.

Philosophy of mind — Asks what a mind is, and how it sits in a body.

The self (personal identity) — Asks what makes you the same person over time, and what “I” refers to.

Other minds — Asks how anyone can know that anyone else has an inside.

Freedom (free will) — Asks whether, and in what sense, you choose what you do.

Possibility (modality) — Asks what it means for something to be possible, necessary, or merely actual.

Ethics — The branch that asks how to act, and what grounds an answer.

Life and moral standing — Asks what life is, and which beings count when we act.

Death — Asks what death is, and what it takes.

The problem of evil — Asks why there is suffering, and what the right response to it is.

Meaning — Asks what a life is for, and whether it needs a purpose given from outside.

Aesthetics — The branch that asks what beauty is, and why art and music move us.

Philosophy of language — Asks what words are, and how they come to mean anything.

Philosophy of physics — Asks what physics says the world is, at bottom, and what observation does.

Cosmology — Asks about the universe as a whole: its shape, its history, and whether it ends.