The tripartite theory of knowledge Michael Lacewing enquiriesalevelphilosophy

The tripartite theory of knowledge Michael Lacewing enquiries@alevelphilosophy. co. uk

Three types of knowledge • Acquaintance knowledge – I know Oxford • Ability knowledge – I know how to ride a bike • Propositional knowledge – I know that elephants are heavier than mice. • A proposition is a declarative statement, or more accurately, what is expressed by a declarative statement – Propositions can go after the phrases ‘I believe that…’ and ‘I know that…’ • We are only discussing propositional knowledge.

Justified true belief • ‘I know that p’: – The proposition ‘p’ is true; – I believe that p; and – My belief that p is justified. • I know that p if these three conditions are fulfilled. And these conditions are fulfilled if I know that p.

Necessary and sufficient conditions • Each condition is necessary for knowledge – You can’t have knowledge without each condition being true. • The three conditions together are sufficient for knowledge – You don’t need anything more for knowledge than each condition being true. • So knowledge and justified true belief are the same thing.

Is justification necessary? • Is knowledge more than true belief? – True beliefs can be held on irrational grounds (prejudice) or just be lucky guesses (astrology) – Knowledge needs a reason, evidence – justification. • However, we sometimes use the word ‘know’ to mean ‘believe truly’ – But this doesn’t capture what we mean by knowledge, strictly speaking.

Is truth necessary? • Could knowledge be justified belief? • We don’t normally say someone can know what is false – E. g. ‘I know that flamingos are grey’ – no, I don’t – I’m mistaken (I think I know, but I’m wrong). • But did people used to ‘know’ that the Earth is flat? • What about our ‘knowledge’ of Newtonian physics? – This is, strictly speaking, false, but works well when not moving at speeds close to the speed of light.

Is truth necessary? • Newtonian physics is roughly true – We know them, roughly speaking. • However, the Earth is not even roughly flat – People did not know the Earth is flat – they were mistaken.

Doing away with truth? • Kuhn (The Structure of Scientific Revolutions): science proceeds by replacing one ‘paradigm’ by another – We can’t compare the two paradigms so as to say that one is false, the other true – Because changes in paradigms involve new concepts – And there is no ‘theory-neutral’ way of describing the evidence.

Doing away with truth? • How scientists describe what they observe depends on the concepts they use. • The main concepts of a paradigm acquire their meaning in relation to the paradigm as a whole. • Therefore, a different paradigm, even if it uses the same term, interprets the concept differently, because it plays a new and different role. • Therefore, different paradigms are talking about different things. • There is no neutral way of describing the world. • Therefore, we cannot compare different paradigms’ claims to say that one is more ‘correct’ or ‘true’ than another, as they could both be correct in their own terms.

Objection • We cannot explain science’s success unless we think it is getting closer to objective truth – Reply: science keeps solving puzzles that face it, but isn’t getting ‘closer’ to ‘the truth’. • There have been no paradigm shifts – There is always overlap in methodology and evidence, so we can always compare paradigms. • We can’t talk about Truth – independent of our concepts; but we can talk about truth – claims that are true or false. • Knowledge can still be justified true belief.

Is belief necessary? • Example: John is very nervous in an exam, and has no confidence in his answers. But his answers are correct, and through his learning, not luck – John knows the answer, but doesn’t believe the answer. • Reply – John doesn’t know the answer – John does know the answer and has an unconscious belief.

Is belief necessary? • Williamson: knowledge is not a type of belief. • Compare perception and hallucination – You only see the tea on the table if the tea is on the table; perception is ‘factive’ – Hallucinating the same scene is a completely different type of mental state – Perception is not hallucinating + extra conditions. • Knowing is also factive (p is true), belief is not factive.

Knowledge and belief • Every attempt to add conditions to belief to turn it into knowledge has failed. • Knowledge is unanalysable • There are different kinds of knowing – perceiving, remembering… • We should understand belief in terms of knowledge • To believe that p is to take p to be true, i. e. to treat p as if you know that p. • Objection: when I make a mistake, I think I know that p, but only believe that p – why, if knowledge is not belief?