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The Big Four: Knowledge, Belief, Truth, Reason

The Big Four: Knowledge, Belief, Truth, Reason. Robert Nola Dept of Philosophy. Topics. Different constructions involving ‘knows’ Different constructions involving ‘believes’ Degrees of belief: psychological and rational What is truth? Defining knowledge. Classical JTB theory.

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The Big Four: Knowledge, Belief, Truth, Reason

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  1. The Big Four:Knowledge, Belief, Truth, Reason Robert Nola Dept of Philosophy

  2. Topics • Different constructions involving ‘knows’ • Different constructions involving ‘believes’ • Degrees of belief: psychological and rational • What is truth? • Defining knowledge. Classical JTB theory. • Examples of knowledge to illustrate the definition • The regress problem. Towards a theory of knowledge • *[A foundationalist theory of knowledge (Descartes)] • *[No knowledge but rational degrees of belief] • *[Truth-Tracking problem for classical JTB theory] • Against Foucault: knowledge not same as power.

  3. §1: Different Constructions of ‘Knows’ (1) • Who/what knows .... People, cats, dogs, dolphins, Martians? • P knows how to .... Skill, ability • speak Chinese, play piano, weave basket, cook karaka berries • Know how to ... comes in varying degrees of skill • Innate know how to ... (breathe, cry, grasp) versus learned know how to ... (fly an aeroplane, etc) • P knows .... By Acquaintance (direct object). - the way home. The Prime Minster. The pope. Green from red; a trumpet from a trombone sound; fossil from a rock. • P knows that .... (sentence/ thought/proposition) Cognitive Knowledge - Aspirin cures headaches; nuts of karaka berries are poisonous

  4. Different Constructions of ‘Knows’ (2) • P knows why .... (Explanatory knowledge) - Aspirin cures headaches; dreams occur; heart pumps blood • P knows how .... (Explanatory - appeal to mechanism) - aspirin cures headaches; heart pumps blood. • P knows what .... - aspirin is; ‘π’ stands for in mathematics; a cube is; dreaming is • P knows when ..., where ..., whether (it is raining), etc • Question: Do any of these kinds of knowing involve others? - knowing how to ... involve knowing that ...? Always? Sometimes? - P knows what aspirin is = P knows that aspirin is acetylsalicylic acid. So, who knows what acetylsalicylic acid is?

  5. §2: Different Constructions of ‘Believes’ • P believes that ..... (competed by sentence/ thought.) Has cognitive content. - Represent content by ‘q’. E.g., q = most birds fly; Fiji is a good place in which to ski; 2+2=4; etc. • Parallel construction to ‘know’? P believes how to ...? P believes why ...? P believes what ...? • P believes in .... (cf. P knows in ...??) - The ACT Party; John Key; P’s mother; P’s lecturers; Air New Zealand; the number 13; God; the Devil; etc • Does: ‘P believes in God’ = ‘P believes that God exists?’ Or something more?? • Does: P believes in X = P has faith in X?

  6. What is a belief that ...? • Do all creatures have beliefs? To same extent as humans? - [Godwits have beliefs about where to fly to?] • Can there be beliefs without language? • Massive number of beliefs + language is what differentiates us from other animals (?). Result of evolution of our brains? • Beliefs are states of the brain/mind. (dispositional, not occurrent states). • Beliefs are representations (in brain/mind) of the world which have meaningful content. They “reach out” to world. • Logical point: P’s belief that q: q can be true, can be false. • Act on our Beliefs. P believes that (say) Fiji is good for skiing. - Has a thought or cognitive content that Fiji is good for skiing - Beliefs are what we act on, steer our lives by. P wants to ski; so P goes to Fiji. • P believes that q = P takes q to be true (?). Belief not just thinking that q, or entertaining, dreaming that q, etc. - Note: p can take q to be true yet q be false (?)

  7. §3: Degrees of Belief • Psychological: your inner feelings of commitment about the belief (content) that q. - Can we have a psycho-meter to measure this? • Rational. Beliefs with and without evidence. • Direct: Beliefs directly based on one’s perceptual apparatus of seeing, hearing, tasting, motion perception, etc. Serve as foundational evidence for other non-evidential beliefs. Transition from seeing a kauri to seeing that it is a kauri. • Indirect or Inferential: Belief that q is based on reasoning from other evidence. Courts of law; science (testing hypotheses); everyday life. • Rational degree of belief: Degree to which you ought to hold a belief given the evidence you have. • Set up a scale of degree of belief from 0 to 1; zero degree of belief to full degree of belief (= certainty?) • Your rational degree of belief that Earth rotates daily? • Different from your psychological commitment?

  8. §4: Truth ‘Definition” or Schema • Aristotle Metaphysics1011b25-26: • To say of what is that it is not, or of what is not that it is, is false; • while to say of what is that it is, and of what is not that it is not, is true. • Example: What is/fact = Auckland has 2 harbours. • To say ‘Auckland has not got 2 harbours’ is to say the false; • To say ‘Auckland has got harbours’ is to say the true.

  9. General Schema as Definition of Truth: q is any proposition, e.g., ‘it is raining now’ FALSE TRUE FALSE TRUE

  10. Comments • We want what we believe, and what we sincerely say, to be true, i.e., to be in accordance with, or correspond to, the world. [Do we? Why?] - Hence “correspondence” theory of truth. • The correspondence holds, or does not hold, whether we believe it or not, or know it or not. • Examples: ‘A container ship is passing North Head now’ • Can say what is true [false] even if you do not know it. • Do NOT confuse being true with knowing it is true or believing it is true. • Are there truths/falsities beyond our powers to know? (In the expansion of π there is no sequence of 7 sevens, 7777777. Everything doubled in size overnight.

  11. §5: Classical Definition of Knowing that ... • P any person (knower); q any proposition. • P knows that q =Defn (1) q is true [Truth Condition] (2) P believes that q [Belief Condition] (3) P has sufficient evidence/reason/justification that q [Justification Condition] • Known as JTB theory of knowledge. • Initially proposed by Plato – Meno (some criticism in Theaetetus) • Forms basis of all subsequent discussion of knowing that in philosophy

  12. All Propositions TRUE Propositions FALSE Propositions PERSON’S CIRCLE OF BELIEFS AT A TIME ?? TRUE BELIEFS FALSE BELIEFS KNOWLEDGE ?? BELIEFS THAT ARE TRUE AND HAVE JUSTIFICATION/REASON/EVIDENCE

  13. The Truth Condition • Truth Condition: we may believe what is false (Bible says: π = 3). But we cannot know it. • If q is false, then do not know that q. • Is our ordinary talk clear on this? No – muddled! • P knows that 2+2=5? • We might think we know , or claim to know – but do not know. • Ancients “knew” that Earth is flat?? • No - believed or claimed to know this. • Did have some evidence for earth being flat – but not sufficient for knowledge.

  14. The Belief Condition • Definition supposes that our beliefs become knowledge when we add evidence for the belief being true. • Belief and knowledge as contrasting: mere belief. • Mere Belief as a first step on the path to knowledge that is then gone beyond. Knowledge is an up-grade! • “I formerly believed that the Earth is spherical; but I no longer believe it (I studied astronomy) – now I know it!” • Mere Belief and knowledge as exclusive of one another. • one has a mere belief without justification or reason. • Knowledge without belief: “I know it but I cannot believe it!”. • Someone dies – you know that. But cannot come to believe it! You have evidence but it has not sunk in.

  15. Why True Belief is not Knowledge • Case of acquiring true belief through unusual causal chain – e.g.., hypnotism. • Child works away and “solves” equations: • x + 2 = 5: Answer: x = 2 • x - 0 = 6: Answer: x = 2 • x + 3 = 5: Answer: x = 2 • x + 2 = 7: Answer: x = 2. • Only 3 is correct. Does child know 3 is correct given wrongness everywhere else? • Chance processes that are lucky – guessing. • Successful persuasion by lawyer in Court

  16. The Justification Condition • P must personally have the justification. Not enough that there be a justification somewhere. • P must work out the justification of q. • Is this condition too strong? • Definition is of inferential knowledge from evidence. • Not a definition of non-inferential or direct knowledge by experience/observation. No justification needed. • Are reports of what we observe direct knowledge without justification? • ‘The lights are on’ versus ‘I am having lights-being-on experiences?’ (Descartes) • I see people v. I am having people-being-here experiences (or: it is as if people are here) • Can only direct reports of experience lack evidence?

  17. §6: Examples from science to illustrate definition • q = Surface of Earth is curved – not flat. • True? Believe it? • Christopher Columbus?? • Evidence for Curvature? Greece 7th BCE. Change in canopy of stars. Or ship at sea. What explains the different lines of sight? Curvature? xxxxx Justification for q: Best explanation is curvature

  18. Eratosthanes 3rd Century BCE Circum (?) 360 AS â = Theorem of Geometry a a Measure 90º-a a A S a C Earth C = Centre Earth S = Syene: Egypt A = Alexandria

  19. Eratosthanes’ Justification • Observation: measurement of angle a • Observation: measurement of distance S to A • Mathematical knowledge (i): geometrical theorem • Mathematical knowledge (ii): model of Sun’s rays and Earth • What is evidence for 1 and 2? Do these need justification? • Evidence for 3? From theorems of geometry – what justification? What proof? • Evidence for 4? • Does a regress of justification threaten?

  20. §7: Agrippa and Regress of Reasons • Agrippa 1st Century CE: Sextus Empiricus. • P knows that q =Defn (1) q is true; (2) P believes that q; • (3) P has sufficient evidence/reason/justification that q. • Spelling out 3: • P has sufficient reason that q = (3a) There is evidence e; (3b) P knows evidence e (not merely believes it or has it); (3c) P reasons from e to q ( p knows how to reason?). Question: Circularity? Define ‘knowledge’ but used in definition on RHS in 3b and 3c! Question: does P need evidence f for e – and evidence g for f – and so on. Infinite Regress?

  21. Agrippa’s Trilemma • Definition of Knowledge is circular – try to define knowledge on LHS – use it on RHS • To avoid circularity, definition leads to an infinite regress of reasons. • To stop infinite regress one adopts an unsupported belief – dogmatism! • So definition of knowledge is circular, leads to infinite regress, or stops at an unjustified belief. • So be a sceptic – there is no knowledge? • Agrippa’s challenge for the JTB definition of ‘knows’: Develop a theory of theory of knowledge to get around Agrippa’s trilemma!

  22. Responses to the Regress • Dogmatism – do not look for reasons for belief! Stop all inquiry! Why bother learning? • Scepticism – there is no knowledge! Why? Give regress argument – so do know something! • Relativism about all knowledge. If all knowledge is relative to me, or to you, why does anyone teach anyone else? • Move from a simple 3-part definition of knowledge to a theory of knowledge. • Foundationalism (Descartes) • Coherence Theory • Probable Belief Theory

  23. §8: Foundationalist Theory of Knowledge • There are foundations to knowledge. Regress stops in certainty. Have beliefs that do not require evidence; non-inferential knowledge. • Example 1: Mathematical self evident truths. (Not all mathematics this way – need proofs) • Example 2: Principles of logic (?) • Example 3: Beliefs based in direct observation • Beliefs about objects: (A) lights are on; (B) grass is green. Will these serve as foundation? • Beliefs about experiences: (A*) I am having lights-being-on experiences. (B) My experience are greeny and grassy! Better foundation?

  24. Questions about Foundations • Can I have lights-being-on experience but lights are not on? • I am having lights-being-on experience; •  the lights are on • Not a secure inference – lights in the brain! A brain surgeon is giving me ‘lights being on experiences’. • Question: Is 1 certain, beyond doubt? • Is 2 certain and beyond doubt? • 2 is not certain. • 2 does not even follow from 1.

  25. Common Sense View: External World as Cause of Experience

  26. Descartes’ Evil Demon: Brain in a Vat!Evil Demon/Computer Causes Experience

  27. Summary of Foundationalism • Beliefs about experiences: I am having lights-being-on experiences. • These are more certain than beliefs about objects such as: the lights are on. • Cannot infer safely from (1) to (2) • Beliefs about ordinary objects are not as certain as the beliefs we have of our experiences ; so cannot serve as the foundations for knowledge. • Beliefs about ordinary objects are fallible. Can we have fallible knowledge?

  28. §9: No Knowledge – Just Rational Degrees of Probable Belief • Replace knowledge that q by high degree of rational belief that q. • Given evidence e: ask how probable is e? • Given some belief q, ask how probable does e make q (given also that e is only probable and not certain!) • Not easy questions to answer. • Arises from need to replace foundationalism and coherentism (not discussed). • Bayesian Probable belief theory (Bayes’ Theorem, due to Thomas Bayes 1702-61)

  29. §10: Truth-Tracking Problem for Classical Theory Real pair of ducks on lake where hunter is not looking. Makes belief true! No truth-tracking! Cause? Duck hunter by lake Justified Belief: There is a pair of ducks on the lake. Reality: pair of decoy ducks on lake – not real ducks. So, false belief!

  30. Stopped clock tells correct time twice a day. Look at clock at 1.32 pm. See hands show 1.32 pm. Have justified belief, on basis of observation, that time is 1.32 pm One looks at exactly 1.32 pm, not moment before or after. So belief is true. But the belief does not track the truth, the true time. Accident that one looks at that time. Stopped Clock 1.32 pm Bertrand Russell’s Stopped Clock

  31. Remedy? • Counter-examples do not touch truth or belief condition. • They concern the justification condition. • Not any justification will do. Need to refine what is meant here. • Do we need a fourth condition that says that the belief must be caused by the fact that makes it true? • The counter-examples seem to ignore that condition. • But is this enough?

  32. §11: Michel Foucault: Knowledge/Power • Slogan. What is ‘/’? • ‘/’ indicates identity: Aphorism of Francis Bacon (1561-1626): knowledge is power. The ‘is’ of identity, being the same as. • P knows that q =Defn P has JTB that q (not the same as power). Does reason/rationality exclude any role for power here? • One-way correlation: If P knows that q does it follow that P has power (over what)? • q = there are people here now. Any power? • q = 2+2=4 (Gives one power to do a bit of maths?) • q = kernel of karaka berry is poisonous (power to kill?) • Bacon: knowing that q (i.e., JTB that q) can enhance human powers (over others, the world) through use of what we know. • Would a mere true belief do this? Does having false beliefs enhance human powers? • Converse Correlation: If one has power then does one know that q? Power for what? Seems false! • Knowledge has justification - norms of reason. Excludes power.

  33. Sociology of knowledge - or belief? • Sociology of “knowledge” is a misnomer. • On JTB theory, what are the causes of your knowing? • Either (i) experience or (ii) reasons for believing on the basis of your evidence where the reasons are good enough to show that your belief is true. • Nothing social here. Norms of reason exclude the social. (norms of reasoning/logic are not social). • Social factors can be a cause of belief, where you believe without evidence {e.g., Earth rotates daily} • If you come to believe on the basis of evidence or reason, then this displaces the social factors.

  34. What has this to do with learning? • Learn how to ...; Learn that ...; Learn why ...; Learn what ... is; • Minimal Working definition of Learning: • David Carr: “whatever is learned in the course of education or related enterprises could hardly be other than a matter of the acquisition of skills, capacities, dispositions or qualities not previously possessed – although it may also be a matter of the development of already given (innate) qualities or potentialities.” • Definition: A person learns that p= the person formerly did not believe that p, but via some process of acquisition, comes to have the belief that p. • The right process turns this from belief acquisition to acquisition of knowledge. The right process is examining reasons, not power or social causes etc.

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