• General Overview
  • Central Thesis: Neutral Monism
    • Neutral stuff: reality's raw material is neither mental nor material; mind and matter are both constructed from it
    • Two scientific drifts: psychology turns behaviouristic, physics dematerializes matter; old materialism collapses
    • Consciousness dethroned: not the essence of mind; a derived relation involving images, beliefs, and mnemic causation
    • Causal dualism: mental and physical differ by causal laws, not by intrinsic subject matter
    • Method: external observation and private introspective data both count; no privileged inner sense
  • Consciousness and Introspection
    • Brentano refuted: intentional object-reference is not ultimate; the "act" is a fictitious ghost of the soul
    • James's pure experience: consciousness is a nonentity; same occurrence can be mental or physical by context
    • Meinong's triad: act, content, object collapses; content alone constitutes thought, reference is derivative
    • Introspection redefined: private, fallible, and useful for images; no separate mental substance is revealed
    • Behaviourism's truth: denies introspection as sole method, but overstates by rejecting images
  • Instinct, Habit, and Desire
    • Mental continuity: no wide gap from protozoa to humans; animal behaviour is a reliable guide to mind
    • Instinct: purposive-looking action without foresight; fallible, plastic, and the engine of learned variation
    • Habit: Thorndike's law of effect and exercise shape trial-and-error learning; all skills rest on instinct
    • Desire: behaviour-cycle driven by discomfort and ended by quiescence; purpose is the cycle's end
    • Conscious desire: primitive desire plus true belief about what will bring quiescence; self-deception breeds secondary desires
    • Psychoanalysis: hidden wishes can govern action while being indignantly denied; desire need not be conscious
  • Mnemic Causation and Memory
    • Mnemic causation: past event plus present stimulus jointly cause present reaction; defines living response
    • Engram hypothesis: Semon's brain-change postulate is theoretical; mnemic causation may be ultimate
    • Memory kinds: habit-memory is routine; knowledge-memory is belief about a past occurrence
    • Memory-images: present image plus a belief-feeling of pastness; comparisons with the past require memory
    • Familiarity and recognition: feelings of degrees; familiarity alone gives no knowledge of the past
    • Specious present: akoluthic fading sensations bridge sensation and image in immediate memory
  • Sensations, Images, and Perception
    • Sensation: non-mnemonic core of perception, neutral between physics and psychology
    • Images: defined causally by association, not vividness; private but observable; thoughts often run on images
    • Perception: sensation plus mnemic filling-out; all actual perception is vague and to some degree confused
    • Matter: a system of appearances/perspectives, not an inferred hidden substance
    • Perspectives and biographies: active place groups physical objects; passive place groups a mind's contents
  • Words, Meaning, and General Ideas
    • Words: physical sound/movement instances; meaning is a natural learned habit, not convention
    • Meaning: causal mnemic effects shared with the object; words can act without images
    • General ideas: no abstract image needed; a particular image represents many by habitual associations
    • Physiological abstraction: repeated similar perceptions blend into a vague composite; contrast with instances yields generality
    • Imageless thinking rejected: verbal and motor habits suffice; no third mental constituent beyond sensations and images
  • Belief and Truth
    • Belief: the central mental fact; truth and falsehood enter through belief's relation to an objective
    • Content: belief is a present complex of words or images; the objective may be past or absent
    • Belief-feelings: memory, expectation, and bare assent are different feelings attached to one content
    • Truth defined: correspondence to fact; self-evidence, coherence, and utility all fail as criteria
    • Verification: expectedness plus future consequences sift beliefs; no belief is absolutely indubitable
    • Causal theory fails: belief cannot be defined by voluntary action alone, nor by uncontradicted images
  • Emotions, Will, and Final Synthesis
    • James-Lange: emotion is the feeling of bodily changes; no irreducible emotional ingredient exists
    • Will: voluntary movement is caused by images of kinaesthetic sensations; decision adds tension and judgment
    • Mental mark: psychological grouping via causal laws, plus subjectivity of perspectives, defines mind
    • Physics and psychology converge: one fundamental science of particulars will underlie both
    • Materialism plausibility: mnemic causation may reduce to physical causation, but certainty is impossible
• Deep Dive
  • Preface
    • Two Conflicting Tendencies
      • Psychology's drift: behaviourists adopt a materialistic method, grounding mind in physiology and external observation
      • Physics's drift: relativity and Einstein make matter less material, reducing the world to "events"
      • Old materialism: receives no support from modern physics, as Eddington's Space, Time and Gravitation shows
    • A Neutral Foundation
      • Behaviourists' insight: physics is the most fundamental science, but that position need not be materialistic
      • Neutral stuff: the world's substance is neither mental nor material; both are constructed from it
      • Sources: William James and the American new realists supply the reconciling view
      • Book's aim: develop neutral monism in detail for the phenomena of psychology
    • Practical Notes
      • Debt: Watson, Nunn, Wohlgemuth, and Muirhead offered valuable help
      • Lecture origins: delivered in London and Peking; the lecture on Desire appeared in the Athenaeum
      • China allusions: merely stand for "a distant country," not geographical claims
  • Lecture I. Recent Criticisms of "consciousness"
    • Refuting Consciousness as Mental Essence (Lecture I. Recent Criticisms of "consciousness" · I)
      • The Project: Refuting the Consciousness Theory
        • Definition deferred: "mental" will be pinned down through the analysis of believing and desiring.
        • Target: a peculiar "consciousness" — a relation to objects or a pervading quality — defines the mental.
        • Two lines of attack: direct analysis; indirect evidence from animals and the mentally ill.
        • Former view retracted: Russell once held the object-reference doctrine; he now rejects it, even for knowledge.
      • Mind and Matter: A Shared Blind Spot
        • Common error: idealists, materialists, and ordinary people all assume they know what "mind" and "matter" mean.
        • Neutral stuff: the world's raw material is more primitive than either mind or matter.
        • Composite constructions: both mind and matter are built from this common, more fundamental stuff.
      • Conventional Psychology's Kinds of Consciousness
        • Perception: crude sensation plus a reference beyond it to the "thing" represented.
        • Memory: consciousness of the past, raising the puzzle of knowing what no longer exists.
        • Ideas: thought of absent objects, in the Lockean sense — "ideas" opposed to impressions.
        • Belief: the conscious mode that may be true or false, yielding knowledge and error.
        • Deferred feelings: desire, pleasure, and pain await Lecture III; cognition will dominate the lectures to come.
      • Brentano: Intentionality as the Mark of the Mental
        • Thesis: every psychical phenomenon is marked by the "intentional inexistence" of an object.
        • Exclusive to mind: psychical phenomena intentionally contain an object; no physical phenomenon does.
        • Russell's rebuttal: the relation to an object is not ultimate; analysis and facts will dissolve it.
      • Meinong's Threefold Analysis of Thought
        • Act, content, object: three elements allegedly combine to constitute any single thought.
        • Act: identical across thoughts of the same kind, indifferent to the particular object.
        • Content: what distinguishes one thought from another; it exists in the mind here and now.
        • Object: may be past, physical, abstract, imaginary, or even self-contradictory.
        • Essential tie: if Meinong is right, no thought can occur without an object.
      • Russell's Two Criticisms
        • The act is fictitious: the occurrence of the content alone constitutes the thought.
        • Ghost of the soul: "I think" misleads; better to say "it thinks in me" or "there is a thought in me."
        • Reference is derivative: beliefs about connections to other elements make up the "object."
        • Content without object: pure imagination runs on without seeming objects or beliefs.
        • Object without content: in perception we confront the physical world, not a mental content.
    • Rethinking Mind, Consciousness, and Knowledge (Lecture I. Recent Criticisms of "consciousness" · II)
      • Realism and Idealism: Contents vs. Objects
        • Idealism: suppresses the object, knowing never escapes thoughts; context leads only to other thoughts.
        • Realism: suppresses the content, claiming direct contact with objects outside the mind.
        • Russell's position: realist about sensation, not about memory or thought.
        • Organic-world thesis: idealism infers the whole from any portion; Russell calls its logic faulty.
        • Realist bias: desire to know an outside world prompts realism, but arguments must be judged on their own.
        • Berkeley's difficulty: sensation seems direct contact; idealists call it mental, but Russell sees no valid grounds.
      • Why Realism Fails for Memory and Thought
        • Memory's problem: remembering occurs now, so it cannot be identical with the past event.
        • Act theory: act of remembering now relates to past event; no logical objection, but act is mythical, unobservable.
        • Without act: memory must contain a present content, landing closer to idealism.
        • Realism remains plausible for sensation, where present object and direct contact fit.
      • James: Consciousness Is Not an Entity
        • James's thesis: "consciousness" is a nonentity, a ghostly echo of the soul; only thoughts as function exist.
        • Knowing is a function: thoughts perform knowing; there is no aboriginal mental stuff.
        • Pure experience: one neutral primal stuff arranged in patterns; arrangements may be mental or physical.
        • No inner duplicity: experience separates into consciousness and content by addition, not subtraction.
        • Paint analogy: same bit of experience can figure as thought in one context, as thing in another.
        • "I breathe": the stream of thinking reduces to breathing; Kant's "I think" becomes observable "I breathe."
      • Neutral Monism and Its Limits
        • American realists: replace "pure experience" with neutral entities; mind and matter are constructed from same stuff.
        • Russell's agreement: sensations belong equally to psychology and physics, hence neutral.
        • Russell's correction: images are mental only; occurrences outside any "experience" are physical only.
        • Causal laws differ: physics and psychology have different laws; sensations obey both, truly neutral.
      • Behaviourism and the Denial of Introspection
        • Watson's behaviourism: only external observation yields knowledge; introspection is not a separate source.
        • Psychology studies behaviour: private mental occurrences, if any, are not scientific data.
        • Animal study origin: observed animal actions undermined inferences to "consciousness"; instincts need no prevision.
        • Language habit: "knowing" in others is observable word-and-behaviour habits, not hidden thought.
        • Cogito challenged: self-knowledge is not radically different from knowledge of others; behaviourists overstate, yet a truth remains.
        • Desire as mark of mind: perhaps desiring, not knowing, is most characteristic of mental life.
    • Desire, Unconscious, and Neutral Monism (Lecture I. Recent Criticisms of "consciousness" · III)
      • Desire and Purposive Behaviour
        • Desire marks life: animals pursue goals; stones only respond to present physical forces.
        • Own motives are inferred: self-knowledge comes from observing actions, not immediate introspection.
        • Conscious desire: desire accompanied by words; words add nothing fundamental.
        • Self-deception: moral blame makes us repudiate shameful motives and cling to virtuous formulas.
      • Psychoanalysis and Unconscious Motivation
        • Unconscious dominance: hidden desires can govern actions and beliefs while being indignantly denied.
        • Psychoanalytic insight: Freud and Jung exposed unconscious wishes in dreams, irrational beliefs, and madness.
        • Treatment shift: delusions often vanish when patients face repressed desires; insanity becomes psychological.
        • Cautious scope: analysts overemphasize sexual wishes; the concealed desire for honour and power also matters.
      • What an Unconscious Desire Is
        • Causal law, not entity: unconscious desire is a tendency to behaviour until equilibrium, like force in dynamics.
        • Primitive and natural: wishes begin unconscious; conscious desire is later, often mistaken theory.
        • Repression is special: Freudian repression occurs, but laziness and current theory usually hide wishes.
        • Watson's biological view: one habit system inhibits another; unfulfilled wishes need never be conscious or repressed.
      • Mind, Matter, and Neutral Entities
        • Neutral monism: reality's stuff is neither mental nor physical; mind and matter are convenient groupings.
        • Interaction obvious: letters influence minds, intentions move bodies; parallelism is unfounded dogma.
        • Methodological independence: study living bodies' laws first; physics' universal sway is an unproved hypothesis.
        • Consciousness dethroned: not the essence of mind; it re-emerges later as a trivial linguistic habit.
  • Lecture Ii. Instinct and Habit
    • Mental Continuity and Vital Movements (Lecture Ii. Instinct and Habit · I)
      • The Principle of Mental Continuity
        • Continuity hypothesis: from protozoa to man there is no wide gap in structure or behaviour, so probably none in mind.
        • Preferable inference: hold mental continuity unless psychological facts refute it; no facts yet do.
        • Two directions: level animal minds up to human intelligence, or level human minds down to animal behaviour.
        • Deciding factor: our choice depends on whether introspection or external observation is the surer psychological method.
      • Self-Knowledge vs. External Observation
        • Self-knowledge advantage: we know our toothaches, thoughts, and dreams directly; others only by testimony or behaviour.
        • Analysis deficit: familiarity with desires and beliefs hides how little we know of their constitution.
        • Introspection fallible: psychoanalysis shows subjective certainty is no guarantee of truth.
        • Needed check: self-knowledge must be constantly controlled by external observation and animal-behaviour theory.
        • Net conclusion: human psychology likely learns more from animals than animal psychology from humans, by degree.
      • Classifying Movements
        • Observable starting point: external psychology begins with movements, physiology, and sounds, not assumed desires or beliefs.
        • James's three classes: voluntary, reflex, and mechanical acts shade into one another through semi-reflex cases.
        • Outside observer's limit: appropriateness marks all alike, so will and consciousness are not externally visible.
        • Mechanical vs. vital: mechanical movements are as if dead matter; vital movements depend on nervous-system properties and are psychology's concern.
        • Instinct vs. acquisition: this distinction, to be examined next, is also one of degree.
      • Stored Energy and Physical Reduction
        • Reducibility: chemistry reduces to physics, and physiology probably reduces to chemistry, at least in principle.
        • Macroscopic vs. microscopic laws: physical reduction holds for the smallest parts, while visible behaviour still follows different macroscopic regularities.
        • Unstable equilibrium: the nervous system stores energy like dynamite or a poised rock, so a tiny stimulus can release vast movement.
        • Postcard example: a few words can generate amazing kinetic energy by tapping the body's stored instability.
        • Psychologist's focus: only vital movements matter; mechanical movements are excluded.
    • Instinct, Habit, and Learning's Roots (Lecture Ii. Instinct and Habit · II)
      • Defining Instinct and Habit
        • Instinctive movement: vital action performed on first occurrence in a novel situation, independent of prior experience
        • Learned movement: behaviour due to previous experience, not what the animal would do without such experience
        • Biological definitions misfit psychology: species-group and welfare clauses are not universal; harmful instincts exist
        • Maturation mimics learning: instincts ripen at different ages, so new behaviour may appear without practice, as with sex instinct
      • Learning as Habit Formation
        • Trial-and-error experiments: cats escape latch cages and rats thread mazes faster with each repetition
        • Law of Effect: responses followed by satisfaction become more firmly connected; discomfort weakens the bond
        • Law of Exercise: repeated, vigorous, enduring connections strengthen a response to a situation
        • Watson's random-movement theory incomplete: recurrence of success cannot explain improvement from the very second trial
        • Further mechanism need not be conscious: Thorndike's laws can be accepted without invoking consciousness
      • Instinct Drives Learning
        • Human learning is not instinct-free: higher animals learn more, but instinct remains the driving force at every stage
        • Random movements are instinctive: they supply the experimental variations from which habits are selected
        • All learned skills rest on instinct: speech begins with instinctive sounds; business routine repeats the cat's latch-lifting
        • Language complicates but does not alter the process: it makes human learning easier and psychologically more complex, but instinct's role remains
      • Instinct Is Fallible and Modifiable
        • Popular infallibility is delusion: instinct is rough-and-ready, easily misled by anything unusual
        • Instinct attaches to wrong objects in infancy: chicks follow any moving object that resembles the mother
        • Fabre's perfect wasp was a myth: Peckhams found Ammophila stinging variable, sometimes failing to paralyse or killing outright
        • Instinct can redirect itself: ants care for Lomechusa beetles and change nursing methods to suit the parasite
        • Experience refines instinct: older stags are harder to deceive by imitated calls than younger ones
      • Nature of Instinct
        • Instinct requires no prevision: it acts without foresight of biological ends, though this cannot be strictly proved
        • Rough outline, not precise adaptation: learning supplies certainty; instinct is only as exact as usual success demands
        • Instinctive processes are improvable: performance often becomes better after experience
        • Instinct initiates learning: it supplies the impulse to experimental movements on which habit formation depends
        • Nascent instincts are plastic: early instincts attach readily to various objects and are easily modified
        • Essence: a mechanism for acting without foresight, usually advantageous biologically
  • Lecture Iii. Desire and Feeling
    • Desire as Behaviour, Not Inner State (Lecture Iii. Desire and Feeling · I)
      • The Commonsense View Reversed
        • Commonsense view: desire is an attitude toward an imagined end, with the end governing action.
        • Similarity to belief: desire shares the content of belief but adds a specific feeling toward that content.
        • Russell's verdict: not logically refutable, yet facts make it simpler to abandon and reverse.
        • Need for reversal: desire should become a causal law of actions, not an entity inside minds.
      • Psychoanalysis and Self-Deception
        • Observed conflict: a patient avows end A while actions visibly aim at a different end B.
        • Hidden wishes: B is usually less virtuous, so the patient is said to hide it in the unconscious.
        • Depth problem: deep instinct regions diverge from conscious desire, making positive self-deception an implausible explanation.
        • Behaviourist re-reading: trust external observation and restate desire in terms of action cycles.
      • Animal Behaviour as Model
        • Cleaner evidence: animals avoid ethical prejudice, conceit, and assumptions of rationality.
        • Actions only: inferring animal minds from actions is dubious, so action alone must test desire.
        • Hunger defined behaviourally: restlessness, searching, sensing, eating, quiescence—not an unobservable mental state.
        • Human extension: the same behavioural explanation applies to human desires.
      • Behaviour-Cycles and Purpose
        • Definition: a behaviour-cycle is a series of movements tending toward a result and continuing until it occurs.
        • Purpose: the result that ends the cycle, normally followed by temporary quiescence.
        • Desire: the animal desires the purpose of the cycle while the cycle is in progress.
        • Two marks: actions appropriate to the result, and persistence until achievement; both are matters of degree.
        • Limits: mechanical movements and interruptions blur the pattern, so desire attribution is not precise.
      • Instinct, Not Prevision
        • Instinctive cycles: reproduction and rearing young cannot be guided by prevision of the final end.
        • Impulsion from behind: each stage is driven by impulse to that act, not attraction from the future.
        • Hunger without ideas: seeking food does not prove the animal has the thought of food in mind.
    • Desire as Behaviour and Self-Deception (Lecture Iii. Desire and Feeling · II)
      • Primitive Desire and Behaviour-Cycles
        • Primitive desire: an impulsion away from the actual, not an attraction toward the ideal.
        • Discomfort sets a behaviour-cycle in motion—hunger starts with an uneasy sensation, then food-seeking actions.
        • Pleasure marks the cycle's end: it stimulates no action, or only actions prolonging it.
        • The hungry animal seems to aim at food, but is actually pushed throughout by discomfort.
      • Discomfort, Pleasure, and Pain
        • Pain is a sensory quality alongside heat and cold; discomfort is its opposite to pleasure, and may accompany any sensation.
        • Confusing pain with discomfort made pleasure and discomfort seem like separate mental contents.
        • Russell defines them as causal properties: discomfort prompts change; pleasure prompts quiescence or prolonging.
        • The intrinsic-quality theory cannot be decided, so causal properties alone are assumed.
      • Consciousness and Belief in Desire
        • Conscious desire = primitive desire plus a true belief about what will bring quiescence.
        • Unconscious desire lacks true belief; all primitive desire is unconscious.
        • Beliefs about a desire's purpose are often mistaken, especially when experience of satisfaction is absent.
        • Inhibiting impulses hides the actions desire would prompt, making errors easier.
      • Secondary Desires and Self-Deception
        • Secondary desire: a false belief about a primary desire generates a real but derivative desire.
        • A jilted person may misread revenge as a wish to travel—yet the travel wish genuinely influences action.
        • Secondary desires bring less satisfaction than primary ones; residual discomfort fuels the sense of vanity.
        • Desire for beliefs: easier to believe excellence or cosmic happiness than to achieve it—hence vanity, optimism, religion.
        • Punishing doubters of such beliefs shows how potent and socially enforced these desires are.
      • Summary of the Analysis
        • Behaviour-cycle: a series of actions caused by discomfort and ending in quiescence.
        • Purpose: the state of affairs whose achievement ends the cycle.
        • Conscious desires have true purpose-beliefs; mistaken beliefs generate secondary desires, complicating—but not changing—the animal basis of desire.
  • Lecture Iv. Influence of Past History on Present Occurrences in Living
    • Mnemic Causation in Living Organisms (Lecture Iv. Influence of Past History on Present Occurrences in Living · I)
      • The Mnemic Character of Organisms
        • Past-dependent response: living response depends on past history, not only present state; this broadly distinguishes organisms from dead matter
        • Burnt child: a burn leaves no visible trace, yet changes the child’s reaction to fire
        • Proximate causation: observed facts include past occurrences among the causes of present response
        • Brain-structure hypothesis: customary but hypothetical; it should not be assumed as fact
        • Biological advantage: mnemic modifications generally improve the organism’s chances
        • Not only living: magnetized steel also behaves differently because of past treatment
      • Defining Mnemic Phenomena
        • Semon’s term: mnemic phenomena are responses whose causal laws require past occurrences, unless brain modifications are assumed
        • Peat-smoke example: recollection is caused by present smell plus the past occasion; the same smell alone fails to produce the same effect
        • Same cause, same effect: since identical present stimuli vary with history, the past must enter the proximate cause
        • Experience: an occurrence is experienced only when it modifies subsequent behaviour
        • Biography: a chain of occurrences linked by mnemic causation
      • Varieties: Habits, Images, Association
        • Acquired habits: cage-learning and answering “Paris” show past experience acting with present stimulus
        • Habitual knowledge: all habitual knowledge consists of acquired habits, hence mnemic
        • Images: images are copies of past sensations and are evoked by present stimuli, as in dreams and speech
        • Association: a present experience tends to call up the context of the former experience
        • Physical habit: drill and animal training associate stimulus and act without requiring anything mental
        • No sharp line: association and habit are not essentially distinct
      • Perception and Memory
        • Perceptual filling-out: familiar objects appear with their usual “real” qualities, not just the sensory core
        • Drawing skill: learning to draw means representing sensation, not perception
        • Space perception: in man, much of sight-touch correlation and space perception is acquired
        • Expectation: hearing a cat bark astonishes because past experience made dog-bark usual
        • Memory knowledge: remembering an event is caused by present reminder plus past occurrence
        • Images and thinking: images’ mnemic character matters because images underlie thinking later
      • Semon’s Mnemic Theory
        • Engram: a stimulus changes equilibrium from a primary to a secondary state; that difference is the engram
        • Engraphic effect: the effect of a stimulus in creating a difference between indifference-states
        • Ekphory: recurrence of part of the original stimulus situation calls out the whole connected reaction
        • Association by engrams: simultaneously generated engrams are associated; any part can arouse the total reaction
        • Inheritance: Semon holds engrams may be inherited, accounting for innate habits
        • Laws: Law of Engraphy and Law of Ekphory combine hypothesis with observable fact
    • Mnemic Causation and the Engram Debate (Lecture Iv. Influence of Past History on Present Occurrences in Living · II)
      • Mnemic Causation Defined
        • Mnemic causation: proximate cause includes a past event together with present stimulus.
        • Single law: if complex stimulus A caused reaction B, part of A later tends to arouse whole B.
        • Dispositions: latent memories are not actual mental contents but mnemic portions of causal laws.
        • Terminology: past items are mnemic cause, present item is occasion/stimulus, result is reaction.
      • Engram Hypothesis as Hypothetical
        • Engram: Semon's postulated material bodily alteration, invoked theoretically, not observationally.
        • Standing differences: if memories are latent, any permanent memory difference must be in the brain.
        • No simplification: introducing the engram does not yet simplify the account of mnemic phenomena.
        • Brain lesions: prove brain state necessary for memory, not sufficient.
      • Causal Laws and the Metaphysical Notion of Cause
        • Uniformities: ordinary causal sequences are approximate, not invariable; invariable laws need differential form.
        • Past can be in cause: no a priori objection to a law whose causal part has ceased to exist.
        • Bergson's error: same stimulus differing effects only shows cause must include past occurrences.
        • Science offers sequences: causal laws are observed uniformities, not felt "operations" or inherent rationality.
      • Psychology, Physiology, and Parallelism
        • Word understanding: response to words depends on past experience, hence mnemic causation.
        • Parallelism rejected: if psychology is independent and physics lacks mnemic causation, parallelism fails.
        • Mnemic phenomena in plants: habit belongs to body as much as mind, weakening purely psychical mnemic causation.
        • Haldane's view: physiology irreducible to physics is possible but requires strong evidence; most physiologists disagree.
      • Weighing Evidence and Conclusion
        • Observation unavailable: no visible brain differences yet between speakers of different languages or recallers of cities.
        • Working hypothesis: past experience affects present behaviour via physiological structure—probably, not conclusively.
        • Keep alternative open: mnemic causation may be ultimate; improbable but possible hypotheses matter for science.
  • Lecture V. Psychological and Physical Causal Laws
    • Causal Laws, Empirical Generalization, Construction (Lecture V. Psychological and Physical Causal Laws · I)
      • From Traditional Cause to Laws of Change
        • Traditional cause: a single event A necessarily producing event B is scientifically obsolete.
        • Continuous change: every “event” is a process, so cause and effect must shrink toward a moment.
        • Differential equations: physical laws express acceleration at each moment, not future positions.
        • Quantized continuity: quantum theory suggests continuity may be apparent only.
      • Empirical Generalizations and Exact Laws
        • Empirical laws: science starts from “A is usually followed by B,” not universal necessity.
        • Exact laws unverifiable: physics’ exact laws are approximate; infinitesimals and infinite divisibility are unobservable.
        • Rough generalizations: they are the data for exact laws and more trustworthy for usual truth.
        • Practical cause: frequent sequence justifies “A causes B” if metaphysical superstitions are dropped.
      • Causation Is Not Unique
        • Nearly invariable antecedent: this is the only applicable sense of “cause.”
        • Lack of uniqueness: every event has many nearly invariable antecedents, each plausibly called its cause.
        • Hooter example: factory hooter and countless other noon hooters equally “cause” workers leaving.
        • Will-derived cause: choosing one antecedent as “the cause” rests on a mistaken analogy with will.
      • Physical Objects as Constructions
        • Table as construction: the object neutral to observers is the set of its observed aspects, not a hidden source.
        • No inferred real table: why assume one common cause for all appearances when aspects can be collected directly?
        • Collected by relations: aspects hang together by similarity and optical laws, not by an inferred single existent.
        • Stellar photography: photographed stars require correlated light-processes at the plate; no aether needed.
        • Physical objects generally: all material things are systems of particulars, not single underlying existents.
    • Appearances, Perspectives, and Physical Objects (Lecture V. Psychological and Physical Causal Laws · II)
      • Appearances and Perspectives
        • Star's effect: at every place, something happens specially connected with each visible physical object
        • Two classifications: group happenings by place, or by correlated system belonging to one object
        • Perspective: all happenings at one place, the view of the world from there
        • Photograph: a recorded perspective; an object's selected appearances across photographs form that object
      • Matter as a System of Particulars
        • Piece of matter: the collection of correlated particulars common sense calls its appearances or effects
        • No hidden entity: no need for an unknown metaphysical thing behind the appearances
        • Appearance: the member of an object's system located at a given place
      • Change: Object or Medium
        • Two change types: only some appearances alter, meaning medium changed; all connected appearances alter, meaning object changed
        • Example: shutting your eyes changes your view; the man leaving changes his appearances everywhere
        • Correlated changes: near-identical simultaneous alterations make common sense treat the system as one thing
        • Physics: deals chiefly with changes where the object's appearances can remain a single causal unit
      • Physics vs Psychology
        • Physics: treats whole systems of appearances as units and states laws in terms of matter
        • Psychology: concerned with actual particulars, especially the appearances themselves
        • Perception: an appearance of an object at a place where sense-organs and nervous system are intervening medium
        • Perspectives and mind: classifying by place is essential for defining what one mind contains
      • Defining Matter Precisely
        • Laws of perspective: generalized intrinsic laws governing how appearances change with position
        • Medium effects: fog, spectacles, telescopes, and sense-organs distort appearances increasingly with distance
        • Limiting set: appearances approach a pure system as we move toward the object; that limit is matter for physics
  • Lecture Vi. Introspection
    • Introspection Falls, Mental Stuff Remains (Lecture Vi. Introspection · I)
      • The Thesis: Sensations and Images
        • Mind–matter dualism: not fundamental; mental stuff can belong to the physical world.
        • Mental life: consists wholly of sensations and images, plus their relations and structure.
        • Sensations: members of systems constituting physical objects; external and bodily correlations yield physical knowledge.
        • Images: defined by causation, not vividness; caused by association, not external stimulus.
        • Knowledge: a sensation or image can become known under suitable conditions, but is not itself knowledge.
        • Images are private: tied to past physical objects, not present ones; hallucination deceives.
      • Introspection as Alleged Inner Sense
        • Orthodox psychology: external perception supplies matter; introspection supplies mental processes.
        • Common sense: seeing a friend is physical; realizing you are glad is mental.
        • Inner sense: Kant called it “inner sense”; also spoken of as consciousness of self.
        • American critics: criticism of introspection has mainly been the work of American psychologists.
        • Conclusion: no separate way of knowing needed; introspection as a distinct method disappears.
      • Stout’s Introspection Criticized
        • Stout’s claim: psychical states become objects only when attended to introspectively.
        • Stout’s further claim: the known object is never identical with the present modification of consciousness.
        • “Psychical states”: demands destructive analysis, not acceptance.
        • Brentano’s object: cognition supposedly contains content and object; the relation is inferential, external—perception is sensations, images, beliefs.
        • Single observer rejected: Dunlap exposes Stout’s illicit “mind watching its own workings”; Russell accepts.
        • Self-consciousness: if object-relation is external, thoughts about mental and physical objects need not differ intrinsically.
      • The Muddle of “Conscious Experience”
        • Three senses: conscious of something, composed of consciousness-stuff, or an experience we are conscious of.
        • Conflation: authors run these three senses together; Russell demands they be separated.
        • External relation: being conscious is like being an uncle—caused by occurrences elsewhere, not self-contained.
        • Verification: to know if you are conscious of a table, inspect correlates, not just your state.
        • No consciousness-stuff: no intrinsic character marks an experience as conscious.
      • James, Dunlap, and the Paradox of Awareness
        • James’s scheme: subject, object, and knowing; subject and object are the same thing at different times.
        • Pure experience: James later dropped consciousness and the thought–reality dualism.
        • Dunlap’s reduction in The Case against Introspection: all James yields is a succession known by a single knower.
        • Knower: no reason to suppose one same knower; only rejected introspection could assert it.
        • Dunlap’s dualism: subject can never become object, so there is no awareness of an awareness.
        • Dunlap’s paradox: knowing exists but is never observed; “I am aware of a colour” is assumed true, no inference supplied.
    • Introspection's Three Questions and Limits (Lecture Vi. Introspection · II)
      • Awareness of Awareness
        • Animal contrast: young children and higher animals know objects, not their own awareness; humans say "I am aware of a colour."
        • Dunlap's burden: he must treat this extra knowledge as purely inferential, but no inference is shown.
        • Russell's inference: the fact that we know awareness exists favors awareness being an object of awareness.
      • Three Questions, Not One
        • Conflated attack: behaviourists and Dunlap mix several distinct questions about introspection.
        • Privacy question: can we observe facts about ourselves that others cannot?
        • Physics question: do observed data obey physical laws?
        • Intrinsic-nature question: do observed data differ in kind from physical constituents?
        • Russell's verdict: yes to privacy, tentatively yes to non-physical images, no to intrinsic difference.
      • Publicity Is a Matter of Degree
        • Publicity scale: sight and hearing are most public; smell, touch, taste less; bodily sensations private.
        • Publicity defined: similar sensations correlated by laws, not identical sensations shared.
        • Perspective: point of view prevents two observers from receiving exactly similar sensations.
        • Privacy is scientific: correlations allow inference, as dentist infers toothache from cavity.
        • Watson refuted: privacy alone does not disqualify a datum from science.
        • Images are private: each image is observable only by one observer, making them introspective in the privacy sense.
      • Images and the Laws of Physics
        • The felt objection: introspective data are disliked mainly because they seem outside physics.
        • Localization puzzle: a visual image fits neither the body nor the physical place it depicts.
        • Current status: images are not yet reducible to physical causal laws.
        • Possible future: images may enter physics, yet stay distinct through proximate causal laws.
        • Proof deferred: Lecture VIII will make the empirical case for images overwhelming.
      • Everything Mental Is Sensations and Images
        • No mental stuff: introspection reveals no elements beyond sensations and images.
        • Mind–matter rapprochement: matter's ultimate constituents are sensations and similar items, not atoms or electrons.
        • Mental construction: thoughts, beliefs, desires, pleasures, pains, emotions consist solely of sensations and images.
        • Third sense rejected: no observation shows a mental world intrinsically unlike physical constituents.
      • Introspection Is Fallible and Open
        • No special certainty: spontaneous self-knowledge is as rash as ordinary external belief.
        • Hidden states: we often fail to notice, or mistake, our own beliefs and desires.
        • Evidence of error: psychoanalysis and forgotten letters show how unreliable self-reports can be.
        • Hypotheses needed: mental operations must be tested by consequences, as in physical science.
        • Relation of knowing: if unanalysable, introspection would be its unique source; if complex, this remains open.
        • Deferred: the full analysis of knowing is promised at the end of the lectures.
  • Lecture Vii. The Definition of Perception
    • Twofold Classification of Particulars
      • Physical grouping: collects aspects of one thing via perspective laws; dynamic laws order successive momentary things.
      • Biographical grouping: collects successive aspects for one observer, then relates sets via perspective laws.
      • Momentary thing: set of particulars gathered by perspective; a thing is a series of such sets by dynamics.
      • Actor example: one plan gives what he does; the other, the impressions he produces.
      • Dualism: every particular belongs both to a thing-group and a biography-group, no mind/matter dualism.
      • Physics assumption: unperceived parts of world are hypothesis, pragmatically justified by simplified laws.
    • Perspectives and Biographies Defined by Time
      • Perspective: set of particulars simultaneous with a sensation; local time, not universal time.
      • Biography: set of particulars earlier, later, or simultaneous with a given sensation.
      • Mnemic phenomena: transform a biography into a life; give continuity of person or mind.
      • Relativity: cross-biography time-relations are logical constructions, not experienced simultaneity.
    • Active and Passive Places
      • Active place: where the object is; source of the aspects collected.
      • Passive place: where percipient or photographic plate is; receives appearances.
      • Every particular has two places: e.g. seeing a star is located both at star and at observer.
      • Subjectivity is not mental: a photographic plate also has passive place and biography.
      • Body vs mind: active group is body/brain; passive group is mind, so far as perceptions.
    • Perception, Sensation, and Mnemic Influence
      • Perception (physical): appearance of an object from a place where a brain or nervous structure exists.
      • Two marks: perceptions cause mnemic phenomena and are themselves altered by past experience.
      • Sensation: theoretical core of perception uninfluenced by mnemic phenomena; perception adds mnemic effects.
      • Vagueness: irregular appearances blend objects, so all actual perception is confused to some degree.
    • External Stimulus vs Central Excitation
      • Regular appearances: due to object alone; actual members of the system that is the object.
      • Irregular appearances: due to object plus intervening medium, not members of object system.
      • Perception defined: mental occurrence tied to external object's appearance; otherwise centrally excited, not perception.
      • Degree not kind: distinction between perception and centrally excited is a matter of degree.
  • Lecture Viii. Sensations and Images
    • Sensations, Images, and Causal Laws (Lecture Viii. Sensations and Images · I)
      • Causal Dualism Instead of Metaphysical Dualism
        • Mind–matter dualism: not metaphysically valid; observed dualism concerns causal laws, not stuff.
        • James's mental fire: imagined fire cannot burn real sticks; mental water need not quench mental fire.
        • Sensation defined: event with physical causes and mental effects; voluntary movement is the converse.
        • Causal distinction not sharp: events have multiple causes; mental laws may reduce to physiology.
      • Sensation as the Non-Mnemonic Core of Perception
        • Sensation definition: the non-mnemonic element remaining after paring away habit and interpretation.
        • Theatre illusion: familiar language fills in unheard words, making inference feel like sensation.
        • Tyre-burst flash: expectation produced a seen flash that was not physically present.
        • Sensational core exists: diverse habits are aroused by diverse sense-data; it is the starting-point of cognition.
        • Not knowledge itself: pure sensation supplies data, but is not a cognitive act.
      • Rejecting Subject, Sense-Datum, and Awareness
        • Old view: sensation was awareness of a physical sense-datum, requiring a subject.
        • Subject is logical fiction: grammar demands it, not observation; logical constructions can replace it.
        • Overlap accepted: a patch of colour can be both physical and psychical, so sensation and sense-datum coincide.
        • Dewey's natural events: perceptions are not cases of awareness; they are like a shower.
        • Historical allies: James, Dewey, Mach locate sensations at the intersection of mind and matter.
      • Images and Their Distinction from Sensations
        • Images are not obvious: dreams, hallucinations, and expectation make images seem like sensations.
        • Vividness criterion fails: Hume's forceful impressions vs faint ideas; sleep, fever, and madness blur them.
        • Belief criterion fails: hallucinations can gain belief; expectation mistakes images for faint sounds.
        • Causal criterion wins: only differences in causes and effects are universally applicable.
        • Hume's insight remains: despite borderline cases, impressions and ideas deserve distinct names.
    • Images vs. Sensations by Causation (Lecture Viii. Sensations and Images · II)
      • Failed Criteria for Imagery
        • Stout's modified Hume: percepts have aggressiveness or force that images lack; sensations can be faint without becoming images.
        • Intense images refute it: Macbeth's dagger and compelling emotions strike the mind as forcibly as any sensation.
        • Feeling of unreality: arises only after an image is recognized as such; dreams feel real, so it cannot define images.
        • Unreality is causal isolation: an "unreal" image lacks the physical correlations a sensation would have.
      • The Valid Causal Distinction
        • Only valid ground: distinguish images from sensations by causes and effects; intrinsic marks fail.
        • Sensations require stimuli: their causes include sense-organs and afferent nerves; images do not need such external stimulation.
        • Mnemic causation: images are occasioned by association from a sensation or image, governed by habit and past experience.
        • Centrally excited caveat: possible physiological causes are hypothesis; mnemic causation is what observation supports.
        • Effects also differ: sensations have physical and mental effects; images' effects follow mnemic laws, not physical laws.
      • Watson's Denial of Images
        • Behaviorist replacement: Watson discards images, reducing them to faint sensations, especially sub-vocal speech.
        • Inner speech is testable: small throat and tongue movements during imagined recitation could be experimentally detected.
        • Visual images defeat Watson: images fill the visual field and lack public physical correlations, so they are not small sensations.
        • Education favors words: Galton showed learned men visualize less; abstract pursuits replace imagery with verbal thought.
      • Images as Copies of Sensations
        • Hume's copy principle: every simple idea resembles and derives from a corresponding simple impression.
        • Complex images may combine: novel compounds are possible, but memory images copy earlier complex impressions.
        • Resemblance grounds reference: images represent absent objects, enabling memory, knowledge, and action.
        • Words overtake images: as education advances, images tend to be replaced by words in thought.
      • Provisional Status and Doubts
        • Distinction not ultimate: Russell doubts the boundary; images may prove a sub-class of sensations.
        • Privacy is no obstacle: images are as observable privately as bodily sensations, which science already accepts.
        • Laws are elusive: imagery occurrence is hard to study because no physical world orders it.
  • Lecture Ix. Memory
    • Memory, Images, and Knowledge (Lecture Ix. Memory · I)
      • Memory as Gateway to Knowledge
        • Pivotal role: memory is presupposed in almost all knowledge, making it the first serious problem of knowledge.
        • Perception: sensation plus habitual associates, subjectively indistinguishable from sensation.
        • Perception's limits: non-sensational elements arise from habit and involve expectations, not recollection.
        • Why memory is hard: memory raises problems that perception avoids, especially the link between present and past.
      • The Problem of Comparing Image with Past
        • Hume's principle: ideas approximately represent impressions; broadly true, but “exactly” overstates.
        • Past prototype inaccessible: the sensation is past when the image occurs, so it can be known only by memory.
        • No direct comparison: image and sensation cannot be jointly present in one experience to test copyhood.
        • Memory theory prerequisite: how images can be known as copies depends entirely on analyzing memory.
      • Present Contents, Images, and Belief
        • Memory-belief is present: everything constituting it happens now, not in the past it refers to.
        • Five-minutes hypothesis: no logical contradiction in a world that began recently with unreal memories.
        • Sceptical hypothesis as tool: shows memory-beliefs must be analysable into present contents.
        • Images without belief: their mere occurrence does not suggest a relation to anything past.
        • Habit not enough: habit itself is only known by trusting memory of earlier similar events.
        • What true memory needs: memory-images must carry belief that they are copies of past occurrences.
      • Feelings of Familiarity and Pastness
        • Imperfect copies: memory-images may be recognized as inaccurate without an imageless memory of the original.
        • Familiarity: the feeling that makes us trust an image; it comes in degrees.
        • Familiarity beats clarity: vivid distorted images are distrusted despite unusual clearness.
        • Feeling of pastness: places an image in temporal relation to the present, aided by context.
        • Context and fading: recent memories have more context; fading akoluthic sensations give just-pastness.
        • Dating remembered events: temporal feelings combine with inference from other remembered events.
      • Vague Certainties and Bergson's Two Memories
        • First datum: there is genuine knowledge of the past, and memory is indispensable to it.
        • Past vs. future asymmetry: past is known immediately, future mainly by calculation.
        • Truth of memory: memory truth is correspondence with a past event, not future usefulness or coherence.
        • Bergson's distinction: in Matter and Memory, habit-memory is routine; true memory recollects a unique event.
        • Habituation of recollection: words used to describe an event can impersonate true memory.
        • Both forms exist: deliberately recalling never-before-remembered facts exposes memory as knowledge.
    • From Habit to True Memory (Lecture Ix. Memory · II)
      • Habit-Memory vs. Knowledge-Memory
        • Habit-memory: past experience changes behaviour without knowledge of the past.
        • Animal/plant “memory”: maze-solving, recitation, inherited habit—not knowledge-memory.
        • Semon's laws cover image revival, not the belief that images refer to past events.
        • True memory is knowledge-memory: belief about past occurrences, not mere habit.
      • The Feeling of Familiarity
        • Familiarity is a definite feeling that can exist without an object, not a cognition.
        • Degrees and unreliability: ranges from vague “seen before” to the déjà vu illusion.
        • Turgenev's Smoke: a haunting heliotrope smell shows objectless familiarity driving search.
        • No past knowledge comes from familiarity alone; the judgment that the familiar was experienced before is reflective.
      • Recognition
        • First sense: knowing what a thing is, e.g. a cat, via habitual association, without past knowledge.
        • Second sense: a belief that “this has existed before”—cognitive and involving the past.
        • Vague “this”: the recognized object is a logical construction, not an identical particular.
        • Against behaviourism: recognition marks the difference between a first and a repeated stimulus.
        • Causal unit: recognition requires two occurrences; psychological laws are not single-event laws.
      • Immediate Memory and the Specious Present
        • Immediate memory retains the just-past in an intermediate state between sensation and image.
        • Akoluthic sensations are sensations in the process of fading toward images.
        • Specious present spans sensation, fading stages, and images, enabling the apprehension of succession.
        • True memory applies only after the fading is complete, when images represent the past event.
      • Memory-Images and Belief-Feeling
        • Memory-images and imagination-images share intrinsic qualities; belief makes the difference.
        • The belief-feeling “this happened” is the distinctive mark of true memory.
        • Three belief-feelings: memory, expectation, and bare assent—pastness lies in the feeling, not the content.
        • Breakfast example: images accompanied by belief are true memory; words without images are habit-memory.
        • Open question: whether memory reduces to habit or association must be examined afresh.
    • Memory, Habit, and Vague Belief (Lecture Ix. Memory · III)
      • The Trigger and Limits of Memory
        • Understanding "this morning" is a habit tied to a time-relation to the present, not a fixed object.
        • A changed familiar room: present objects call up an image of absent blank wall; clash with perception provokes memory.
        • Habit explains why present feature brings memory-image, but not the memory-belief itself.
        • Provisionally accept Bergson: memory-belief cannot be reduced to habit when it first occurs.
      • What Memory Judges
        • Memory-belief gives the memory-image "meaning": it points to an object that existed in the past.
        • Simplest memory judges "this occurred," where "this" vaguely covers both the image and its prototype.
        • Ordinary speech does not distinguish identity from close similarity, so primitive memory is vague but not false.
        • Confounding image and prototype feeds philosophical myths: Bergsonian interpenetration, Hegelian identity-in-diversity.
      • Vagueness and Accuracy
        • Accuracy is proportional to reacting differently to slightly different stimuli; precision is narrowness of verifying occurrences.
        • A memory is vague when many occurrences verify it, precise when only a narrowly circumscribed occurrence would.
        • Vague beliefs are likelier true than precise ones but less valuable: putty covers the bull's eye, a bullet distinguishes.
        • Vague words are not general words: they apply to objects not distinguished, while general words mark a common property.
      • Analysis of Pure Memory
        • Pure memory demands an image plus a belief in past existence; the belief may be expressed "this existed."
        • The reference to the past lies in the belief-feeling, not in the content believed.
        • The wordless content is an image, a feeling of reality, and a relation of reference.
        • The feeling of reality is akin to respect: it marks what can affect us without our voluntary co-operation.
        • Verbal content is best "the existence of this": "this" is vague, "existence" expresses reality-feeling.
  • Lecture X. Words and Meaning
    • Meaning as Natural Habit (Lecture X. Words and Meaning · I)
      • Words as Physical Occurrences
        • Word: a set of similar spoken movements or heard sounds, not a single unique entity.
        • Instances: each use is a series of mouth-and-throat movements; similarity among instances is a matter of degree.
        • Spoken words: emphasized over written because more important for analyzing thought, though both are sign occurrences.
        • Meaning: the distinguishing feature that turns physical movements into a word; defining it remains the problem.
        • Physical basis: speaker's movements and hearer's sounds are connected causally, not by inherent resemblance.
      • Meaning Is Natural, Not Conventional
        • Conventional origin: myth; new terms may be coined, but a language's basis is learned, natural habit.
        • Growth: language is learned from environment and modified by causes, not by deliberate design.
        • Sign systems: gesture, ants' antennae, and Chinese writing show language is not tied to speech.
        • Essence: fixed associations let a sensible sign call up the idea of something else.
        • Private use: language affects thought chiefly through unheard inner speech, not just social utterance.
      • What Words Can Mean
        • Proper names: denote a causal series of occurrences—Napoleon changes gradually; no simple ego is empirically needed.
        • Particulars: ultimate brief existents never receive proper names; language was invented for practical ends.
        • General names: "man" groups similar collections of particulars by common properties, unlike causal proper names.
        • Process words: "eating," "walking," "lightning" name sets of similar occurrences; no sharp line from proper names.
        • Quality and relation words: "white" denotes static similarities; "above" and "before" are more abstract and logically simpler.
        • Grammar caution: "rain" and "to rain" show grammatical parts of speech can mislead; avoid metaphysical weight.
      • Understanding as Habit
        • Active and passive: understanding is using a word on suitable occasions and acting appropriately when hearing it.
        • Non-definitional: understanding is more like knowing cricket than reciting dictionary definitions.
        • Vagueness: meaning is a target with a bull's eye and a gradually diminishing outer region; precision never eliminates it.
        • Correctness: psychological, not literary: the average hearer's response decides whether a word is correctly used.
        • Causal law: a word's meaning governs use and response as laws govern planets; users need not know it.
      • Situations Revealing Understanding
        • Motor warning: Englishman leaps aside without ideas; understanding can be purely physiological habit.
        • Frenchman: translates internally before acting; inner speech may be incipient or merely imaged.
        • Child learning: pointing and scene give new word its meaning; word acquires some causal efficacy of the object.
        • Four ways: proper use, appropriate action, association with another word, association with an object.
        • Shared effects: word shares only vital and mnemic effects with its object, never physical force like breaking bones.
    • Words Beyond the Present (Lecture X. Words and Meaning · II)
      • Narrative and Imaginative Uses
        • Demonstrative vs narrative: demonstrative words point at present sensations; narrative words intend memory- or imagination-images.
        • Memory meaning: child recalls a past motor-car; words describe a picture, not an actual object.
        • Telescoped word-habit: words can operate without images, as in reciting a known poem; meaning then latent rather than active.
        • Two new modes: words may describe/recall a memory-image, or describe/create an imagination-image with belief.
        • Thinking depends on images: in origin, verbal thought brings us into touch with what is remote in time or space.
      • Habit Without the Object
        • Watson's gap: behaviourist account explains saying "box" when present, but barely explains calling "box" in its absence.
        • Association fills absence: sensations or images frequently contiguous with a word can, by habit, cause the word later.
        • Desire not a true cause: desire is a convenient fiction like force, not a distinct occurrence explaining images or words.
        • Habit suffices: the law of habit can account for absent-object words theoretically even without images.
        • Images undoubted but unproved: word-use gives no fresh argument for images, since a purely behavioural explanation remains possible.
      • Images and Meaning
        • Image meaning: likeness plus causal effects, not one exact prototype; vague images can mean "dog" in general.
        • Causal criterion: image or word has same mnemic effects as the object; generality or particularity is a matter of degree.
        • Limit of meaning: identical effects defeat particularity; total generality like "entity" would lack mnemic effects and meaning.
        • Berkeley and Hume corrected: they treated images as definite like physical objects; vagueness is what enables general ideas.
      • Words as Instruments of Thought
        • Word meaning: constituted by mnemic causal laws, not likeness; word "dog" has the associations of dogs without resembling them.
        • Associations suffice: intelligent use needs right associations with words and actions, not necessarily images.
        • Advantages of words: easy to produce, concrete for abstractions, and highly uniform instances help thinking about kinds.
        • Danger of verbal tyranny: grammar may distort metaphysics; avoid assuming sentence structure mirrors fact structure.
        • Vision plus words: direct imagistic contemplation checks verbal habit, but outcome must be expressed in words; rare capacity combines both.
  • Lecture Xi. General Ideas and Thought
    • Abstract Ideas and Physiological Abstraction (Lecture Xi. General Ideas and Thought · I)
      • The Logical Problem of Abstract Words
        • No abstract content implied: intelligent use of abstract words proves nothing about a mental idea.
        • Mechanical language: a machine could say "There is a dog" when a dog appears; correct speech is just behavior.
        • Words as substitutes: general words replace dissimilar particulars with very similar word-instances, so logic leaves theory open.
      • Berkeley's Rejection of Abstract Ideas
        • Berkeley and Hume: attacked "abstract ideas," meaning images, not logical entities.
        • Locke's claim: abstract general ideas separate man from beasts — the special dignity of reason.
        • No abstract image: any imagined hand, eye, or man has particular shape, color, and size.
        • Generality by representation: one particular line stands for all lines, so no abstract content is needed.
        • Elitist consequence: if abstraction is the test, most humans are as incapable as brutes.
      • Semon's Physiological Abstraction
        • Berkeley's gap: images usually blend many related similar prototypes, not one definite original.
        • Composite images: repeated similar perceptions fuse into a generalized picture, like composite photographs.
        • Pre-logical abstraction: physiological abstraction precedes logical abstraction and appears in higher animals too.
        • From vague to general: the composite image alone is vague; particular images of instances make it function as general.
      • Distinguishing Vague, Particular, and General
        • Content test: generality needs particular images compared with the generalized image, not a new abstract content.
        • Reaction test: a vague word like "Smith" fits many individuals but each as an individual.
        • General word: "man" differs from individual reactions — we say "This is a man," not "This is man."
    • General Ideas, Imageless Thought, Universals (Lecture Xi. General Ideas and Thought · II)
      • General versus Vague Ideas
        • General idea: differs from vague idea by an accompanying belief that no one individual is represented.
        • Vagueness: every image has some vagueness; the occurrence could vary within limits without recognizably changing the image.
        • Contrast required: the general becomes definable only alongside relatively precise particular images or words.
        • Ribot's view: the generic image is never a judgment; the concept always is.
      • Critique of Thought-Psychology Experiments
        • Questionnaire method: Russell echoes Wundt's verdict that these are "counterfeit experiments," not scientific methodology.
        • Introspection unreliable: reports are easily falsified by preconceived theory, like a shortsighted man expected to see Jones.
        • Buhler's "thoughts": alleged imageless "awareness that..." and known rules, independent of sensuous presentation.
        • Telescoped processes: Russell explains such reports as habitual elisions, not evidence for a revolutionary view of thought.
      • Imageless Thinking and Habit
        • Imageless thinking: Russell rejects the claim that thinking can proceed neither in words nor in images.
        • Habitual behavior: Thorndike's animals link stimulus directly to movement, without a non-physiological intermediary.
        • Speech as habit: much talk is a habitual response to a sensory situation, needing no intervening thought.
        • No "ideas": there is no good evidence for ideas as a third mental constituent beyond sensations and images.
      • Universals and Meaning
        • Causal view: mental content is always particular; what it means depends on its causal connections, not intrinsic character.
        • Horse and bear: reacting to any instance of "smell of a bear" does not imply consciousness of the universal.
        • Consciousness of universals: exists only as reflective judgment observing similarities and differences.
        • Universals inferred: they may be part of the world's structure, but they are not presented as single objects to the mind.
      • Knowledge of Universals and Behaviourism
        • Verbal habit: knowing "dog" means using the word rightly; the logician's further stage investigates similarities and differences.
        • Generic image: formed by superposition or homophony of perceptions; vague unless knowingly contrasted with instances.
        • Images unnecessary: intelligent speech could be a motor habit without images, so behaviourist psychology remains possible.
      • Limits of Behaviourism
        • Subjectivity of physics: the physical world as known is infected with subjectivity; relativity reintroduces points of view.
        • Private observations: introspective data must be trusted despite privacy, because even physics depends on such observations.
        • Images retained: since remote knowledge relies on them, images are not to be rejected merely for being introspective.
  • Lecture Xii. Belief
    • Belief's Structure and Objective Reference (Lecture Xii. Belief · I)
      • Belief as the Central Mental Fact
        • Central problem: belief is the most mental phenomenon, the pivot of the whole intellectual life.
        • Vehicles of truth: beliefs give knowledge and error; psychology, theory of knowledge, and metaphysics revolve around them.
      • Five Requisites for a Theory
        • Truth and falsehood: beliefs, like words, have meaning; they are true or false by relation to an external fact, the objective.
        • Non-intrinsic truth: a belief's truth value lies in its reference to its objective, not in its intrinsic nature.
        • Believing vs content: the believing act is an experienced feeling, constant across different contents; memory, expectation, and assent are forms.
        • Content is present: what is believed is a present event, never the objective itself, as in "Caesar crossed the Rubicon".
        • Knowing is external: the content-objective gulf only seems skeptical; knowing is a complicated causal relation like a signpost pointing to a town.
        • Reference from meaning: objective reference derives from meanings of content constituents, though single meaning yields true-or-false reference and memory-belief may be more primitive.
      • The Content of a Belief Is Complex
        • Complex structure: every belief content has multiple constituents in definite relations; "Plato preceded Aristotle" and its converse differ.
        • Making recognition: hearing a tram and thinking "tram" joins sensation and word or image by predication—a judgment of perception.
        • Constituents: contents may be words, images, or sensations used as signs; at least one word or image is required.
        • No bare sensations: objective reference is essential and derived from meaning, so sensations alone cannot constitute belief.
        • Symbols vs objects: sensations used as signs occur as symbols; the objective contains their meanings, but only the sensations in their own right.
      • Image-Propositions and Word-Propositions
        • Two simplified cases: beliefs may consist wholly of images or wholly of words; mixed contents are not specially important.
        • Corresponding contents: imaging a familiar room with the window left of the door and saying "the window is left of the door" share one objective.
        • Images are not richer: image-contents are vague and fragmentary; words can capture all their meaningful features.
        • Propositions: a proposition is a meaningful series of words or images—the content of actual or possible belief.
        • Compositionality: word meanings plus syntax determine propositional meaning, so novel sentences can be understood at once.
    • Belief, Images, and Propositional Attitudes (Lecture Xii. Belief · II)
      • Propositions and Image-Beliefs
        • Propositions versus beliefs: logic concerns truth-conditions, so propositions are simpler except when actual belief is analyzed.
        • Image-propositions are primitive: memory-images with belief-feeling may predate language and occur in higher animals.
        • Perception is sustained by image-beliefs: visual objects rouse tactile images, giving different perceived qualities to a sofa and a block of marble.
        • Unspoken expectations are beliefs: habitual perceptual beliefs reveal themselves by surprise when disappointed, even if never put into words.
      • Attitudes Toward One Content
        • Same content, many attitudes: one can expect, remember, doubt, entertain, desire, or fear “an egg for breakfast.”
        • Conative attitudes excluded: desire and aversion were handled earlier; only cognitive attitudes are analyzed here.
        • Three cognitive belief-kinds: memory, expectation, and bare assent differ by belief-feeling, not by content.
      • The Causal-Efficacy Theory
        • Causal definition: a content is believed when it causes voluntary movements, just as meaning was defined by associations.
        • Disposition versus active belief: “always believing” means readiness; the theory must define the active occurrence.
        • Non-actional beliefs refute it: active historical or mathematical thinking may cause no voluntary movement at all.
        • Same content, different effects: believing and considering differ in effects, so they must differ intrinsically.
      • The Uncontradicted-Image Theory
        • Spinoza–James thesis: any object remaining uncontradicted is ipso facto believed and posited as absolute reality.
        • Belief as absence of counter-force: doubt and disbelief are positive inhibitions; a mere image tends to have dynamic belief-power.
        • Supports dreams and development: hallucination and childish assent fit, but judgment and suspense are sophisticated products.
        • Fails memory and mathematics: uncontradicted images cannot explain remembering or beliefs that issue in no proximate action.
      • Belief-Feelings and Their Relation
        • Belief-feelings: memory, expectation, and bare assent are feelings or sensation-complexes attached to the content believed.
        • Specific relation required: a memory-feeling must attach to the remembered proposition, not merely coexist with any present content.
        • Words obscure temporal kinds: “I ate breakfast” and “Caesar conquered Gaul” share verbal form but differ psychologically.
        • Detached belief-feeling: abnormally strong conviction may seek a content, explaining some revelation and mystic insight.
  • Lecture Xiii. Truth and Falsehood
    • Truth, Knowledge, and Behavioural Accuracy (Lecture Xiii. Truth and Falsehood · I)
      • Why Mind Analysis Must Face Truth
        • Truth and falsehood: defined by relation to facts, which may lie outside the believer's experience.
        • Psychology alone cannot distinguish true from false beliefs; only relation to fact can.
        • Belief yields knowledge only when true, so analysis of mind must examine knowledge.
        • Four problems: behaviourist knowledge, intrinsic criteria, verifiability, formal definition.
      • Knowledge as Accuracy of Response
        • Behaviourist view: knowledge is inferred from bodily movements, especially speech and writing; important but not exhaustive.
        • Accuracy requires different responses to stimuli differing in relevant ways.
        • Accuracy requires same response to stimuli not differing relevantly.
        • Child and weather-cock fail by fixedness or randomness, not varying with relevant stimulus.
        • Relevant ways depend on purpose: question meaning matters; voice loudness does not.
      • Knowledge Reaches Beyond the Stimulus
        • What is known may differ from the stimulus; the calendar's stimulus yields knowledge of future Easter.
        • Sense-knowledge alone identifies stimulus with what is known; memory and abstract facts do not.
        • Perceptual knowledge counts: a bird avoiding branches responds accurately to visual stimuli.
        • Habit memory: the remembered event is an essential cause, at one remove, of the remembering.
      • Appropriateness and Purpose
        • Accuracy and appropriateness can conflict: with a tiger behind you, turning round is accurate, running away is apt.
        • Accuracy alone cannot distinguish a believer of truths from one of falsehoods.
        • A reversed thermometer could be as accurate; a false believer is as sensitive but perishes.
        • Appropriateness means response suits the agent's purpose; if the aim is deception, falsehood shows knowledge.
        • Calculating machines give perfect accuracy, yet lack purpose, so we deny them knowledge.
        • Voluntary movement is required for appropriateness in knowledge-responses.
      • Self-Evidence Fails as an Intrinsic Criterion
        • Intrinsic criteria sought to make truth easier, but attempts are not encouraging.
        • Mutual coherence and self-evidence are the two proposed tests.
        • Self-evidence is not certainty: one person's indubitable may be another's doubtful (e.g., Antipodes).
        • Meinong's self-evident self-evidence leads to infinite regress, not practical certainty.
        • Mathematical self-evidence reflects decisions about symbols, not facts about the world.
        • Perceptual self-evidence ("buttercup is yellow") is vague; precise comparisons gain more certainty.
    • Truth, Verification, and Correspondence (Lecture Xiii. Truth and Falsehood · II)
      • Self-Evidence and Coherence Fail as Criteria
        • Pursuit of precision: no strict limit; similarity is not prima facie measurable, so simple criteria cannot be final.
        • Self-evidence: no intrinsic quality marks a judgment as infallible; habit often drives subjective certainty.
        • Perception judgments: most involve correlations or recognition, hence always liable to error (e.g., mistaking marigolds for buttercups).
        • Coherence theory: Joachim's The Nature of Truth holds one truth logically compels the whole of truth; but logic is weaker.
        • Coherence objection: a consistent fairy-tale can be wholly false; harmony with other beliefs is not truth.
        • Leibniz's possible worlds: accord better with modern logic than monistic inference of all truths from one.
      • Verification as the Practical Test
        • No absolute criterion: no beliefs are guaranteed error-free; no test can test itself without begging the question.
        • Verification: the happening of something expected—first an image with expectation, then a sensation with the feeling of expectedness.
        • Causal view: appropriate action during expectation adds confirmation but is not essential; expectedness is what counts.
        • Indirect verification: scientific and historical claims are confirmed by deducing future-observable consequences (manuscripts, inscriptions, causal laws).
        • Practical sifting: verification raises assent to confirmed beliefs, lowers it to falsified ones, and builds science without refuting the sceptic.
      • Objective Reference and the Direction of Belief
        • Propositional objective: unlike word meaning, proposition's reference involves a duality of truth and falsehood, not true and false facts.
        • Pointing toward/away: a true belief points toward its objective; the contradictory false belief points away from the same objective.
        • Hypothetical meaning: we know a proposition's meaning by knowing what would make it true and what would make it false.
        • Word "not": contradictory propositions share one objective but have opposite meanings; one is true iff the other is false.
      • Formal Correspondence
        • Image-propositions: memory-image of window left of door is true when the same relation relates imaged terms and actual terms.
        • Words break simple correspondence: relation-words are solid terms, not relations, so word-propositions have more terms than their objectives.
        • Atomic propositions: replace each word by its meaning; if the result is a fact, the proposition is true.
        • Negative propositions reverse: "Socrates does not precede Plato" is true when the objective verifying the positive proposition is absent.
      • Complications: Negatives, Relations, and Adequacy
        • Negative facts exist: image-propositions are always positive, yet disbelief can be true when the imagined fact is absent.
        • Language is positive: negative facts are symbolized by positive word-facts like "does not precede," not by omission.
        • Three dualities: positive/negative facts, believed/disbelieved image-propositions, and word-propositions verified by positive or negative objectives.
        • Unimaginable relations: "sun brighter than moon" requires comparison beyond coexistence of images, so formal correspondence is not simple.
        • Formal adequacy not enough: the theory doesn't explain preference for true beliefs; that requires causal efficacy, purpose, and appropriateness.
  • Lecture Xiv. Emotions and Will
    • The James‑Lange Theory
      • James's reversal: bodily changes follow the perception directly; feeling those changes is the emotion.
      • Common sense inverted: we feel sorry because we cry, angry because we strike, afraid because we tremble.
      • Without bodily states: perception would be pale, colorless, destitute of emotional warmth.
    • Evidence and Debate
      • Angell's defense: James's essential contention survives the experimental criticisms of Sherrington and Cannon.
      • Sherrington's surgery: emotion persisted after spinal severing, suggesting visceral expression is secondary, reinforcing rather than initiating emotion.
      • Cannon's adrenin: pain, fear, and rage alter adrenin secretion; injected adrenin can produce fear symptoms.
      • Cannon's objection: similar visceral states accompany different emotions; reply‑‑visceral differences may still exist, e.g. fear tenses muscles, joy relaxes them.
    • The Analysis of Emotion
      • No separate class: emotions are complex processes, not irreducible mental ingredients.
      • Sensations and images: an emotion's cross‑section is a perception—of viscera (James) or external stimulus (opponents).
      • Process not stuff: desires, pleasures, and pains are characteristics of the process, not separate components.
      • Pattern: emotion consists only of sensations, images, and bodily movements succeeding in a definite pattern.
    • Will and Voluntary Movement
      • Voluntary movement: movements caused by images of their own kinaesthetic sensations, after prior involuntary occurrence.
      • No behavioural line: reflex and voluntary movements cannot be distinguished from outside; the difference lies in ideational causation.
      • Emphatic volition: decision after deliberation adds judgment, tension, and exclusive motor imagery.
      • No new ingredient: will is analyzable as sensations, images, relations, causal laws, and kinaesthetic imagery prompting movement.
  • Lecture Xv. Characteristics of Mental Phenomena
    • Distinguishing Mind from Matter (Lecture Xv. Characteristics of Mental Phenomena · I)
      • The Question and Provisional Answer
        • Mind vs matter: psychology and physics are distinguished by their causal laws, not by their subject matter.
        • Images: the only exclusively psychological subject matter, but definable only through causation, not intrinsic character.
        • No intrinsic mark: sensations and images cannot be told apart by what they are in themselves.
        • Neutral stuff: mind and matter are constructed from one neutral stuff whose causal laws underlie both physics and psychology.
      • Consciousness Defined
        • Consciousness is not fundamental: it is complex, must be of something, and is not a diffused character of all mental life.
        • Definition: a copying image plus belief that it signs something other than itself makes the sensation conscious.
        • Belief is essential: mere imagination does not amount to consciousness; belief supplies objective reference, past or present.
        • Truth clause: the beliefs involved must be true, otherwise we could be “conscious” of the nonexistent.
        • Sensation vs consciousness: a sensation itself is not conscious; immediate memory makes it an object of consciousness.
      • Perception and Introspection
        • Perception: present sensation plus expectations of future sensations; this is reflective analysis, not naive introspection.
        • Expectations are fallible: they rest on usual but not invariable correlations, as when a reflection is mistaken for a real object.
        • Judgment of perception: a core of sensation plus associated images, with belief in present existence of an object.
        • Consciousness of images: an image can mean another image of the same prototype when distinctive associations are active.
        • Introspection: an associative account can explain awareness of images without requiring images of images.
      • Mnemic Causation and Signs
        • Practical essence of thought: acting by signs with reference to what is absent in time or space.
        • Signs: sensible A, as sign of B, enables action appropriate to B; words are the supreme example.
        • Consciousness not always needed: well-established habits make signs operate directly without imagery or consciousness.
        • Acquired experience: a burnt child fears fire because past burning and present fire together form the cause of behavior.
        • Neural explanation: memory and experience may be brain changes; hence mnemic causation is too wide to define mind.
      • Subjectivity and Biographies
        • Subjectivity: the characteristic of perspectives and biographies—the view of the world from a certain place.
        • Perspective: all particulars appearing from one place at one time; biography is a perspective through a period of time.
        • Not sufficient for mind: photographic plates exhibit subjectivity; it involves no consciousness, experience, or memory.
        • Passive place: the “passive” place of a particular is an essential element in defining mind.
        • Presupposed by mental phenomena: mnemic causation and perception require perspectives, and engrams involve perspectives in living tissue.
      • Data and Knowledge
        • Data defined epistemologically: propositions whose truth is known without demonstration, usable as premisses.
        • Objects as data: objects become data when perception assures us of their existence.
        • Belief is prerequisite: a sensation that merely comes and goes is not a datum; it becomes data only when remembered or judged.
        • Data are complex: they depend on consciousness, hence on beliefs and mnemic phenomena.
        • Datum relation unfinished: connecting this epistemological notion with psychological analysis is required but not yet secured.
    • Data, Causal Laws, and the Unity of Science (Lecture Xv. Characteristics of Mental Phenomena · II)
      • The Status of Scientific Data
        • No datum is indubitable: every belief is fallible and somewhat vague.
        • Data are learned, not earliest: trained observers isolate what grounds a science.
        • Perception's core: ultimately only sensations are data in physical science.
        • Nerves are inferred, not seen: "seeing a nerve" is like "hearing a nightingale" — a convenient fiction.
      • Physics and Psychology Share Their Material
        • Sensations are psychological data: so all physical data are also psychological.
        • Images may be exclusively psychological: they belong only to psychology's data.
        • Physics groups by active place: appearances of the same piece of matter.
        • Psychology groups by passive place: appearances in the same perspective.
        • Matter is a logical fiction: inferred from appearances, never itself a datum.
      • Causal Dependence and Materialism
        • Causal dependence is many-one: nearer appearances allow inference to distant, not conversely.
        • Sensations share distant appearances' dependence: our sensational life is subject to physical laws.
        • Materialism asks: is every mental phenomenon causally dependent on physical phenomena?
        • Evidence points to materialism: mnemic causation probably reducible to physical causation in nervous tissue.
        • Not certain: the question may be insoluble with current knowledge.
      • Psychological Laws: Tendency, Not Precision
        • Habit and association are rough laws: statistical averages, not invariable predictions.
        • Wohlgemuth's association experiment: earlier-to-later for motor memory; visual and auditory recall in both directions.
        • Precise laws require physiology: repetition modifies brain paths like a river wears a channel.
        • Psychophysiology is materialistic in method: even when not in metaphysics; Haldane's impossibility claim is exceptional.
      • A Unified Science of Particulars
        • Fundamental science states causal laws of particulars: not of matter as a fiction.
        • Physics becomes derivative: as chemistry is derivative from atomic theory.
        • Psychology loses its isolation: the unifying science applies to both equally.
        • Right philosophy of matter dissolves mind-body perplexities: ancient difficulties arise from a wrong one.
• Core Conclusion and Practical Takeaways
  • Core Philosophical Conclusions
    • Neutral monism: one neutral stuff underlies both mind and matter; both are constructed from it.
    • Consciousness is not an entity: it is not the mark of mind; a trivial, often linguistic habit.
    • Sensations and images: all mental life consists of sensations, images, and their causal relations.
    • Mnemic causation: past experience enters the cause of present response; memory and habit share the same basis.
    • Causal laws, not substance: psychology and physics differ in causal laws, not in subject matter.
    • Truth is external: beliefs are true by reference to facts, not by intrinsic self-evidence.
  • Practical Practices from the Analysis
    • Observe behaviour first: infer desires and beliefs from action cycles, not from introspective claims.
    • Trust external checks: control self-knowledge with external observation and animal-behaviour evidence.
    • Define desire by cycles: treat a desire as the purpose of a behaviour-cycle—actions toward a result until quiescence.
    • Test beliefs by verification: accept confirmation when expected sensations happen; lower assent when expectations fail.
    • Analyze memory as present content: locate belief-feelings and images now, not in a mysterious past contact.
    • Use privacy scientifically: private data like images can be evidence via correlations, as dentistry infers pain.
  • Learning, Memory, and Habit
    • Strengthen habits by exercise: repeat and practice responses to situations; satisfaction cements the bond.
    • Use instinct as fuel: begin with instinctive impulses and let random movements supply variation for habits.
    • Train memory with context: associate a present reminder with the past occasion; context makes recollection vivid.
    • Recognize familiarity is not knowledge: a feeling of "seen before" is fallible; check it against evidence.
    • Prefer words plus concrete images: combine verbal thought with direct imagistic checks to break verbal tyranny.
  • Mindset Shifts
    • Abandon the ghost of the soul: say "there is a thought," not "I think," to avoid inventing a subject.
    • Level mind with animal behaviour: human psychology learns more from animal experiments than from introspection alone.
    • Reject infallible instinct: treat instinct as rough and modifiable, requiring experience and habit for precision.
    • Distrust verbal habits: grammar can distort metaphysics; don't mirror sentence structure onto fact structure.
    • Accept fallible introspection: self-reports are hypotheses to be tested, not certain data.
    • See matter as a construction: treat physical objects as systems of appearances, not hidden metaphysical things.