What Is Knowledge?

1. What Is Knowledge?

2. “What Is” Questions Philosophers are often concerned with “what is” questions: what is the mind? What is moral goodness? What is truth? What is beauty? What is knowledge?

3. Essences Here we want to know the essence of these things. When we ask “What is moral goodness?” we don’t mean “Which things are good?” but “Why are certain things good?” “What is it about them that makes them good?” “What is the essence of moral goodness?”

4. Why Should We Care? Not all questions about essences are interesting or worth caring about. • “What is the essence of garbage?” • “In virtue of what is something a table?” Philosophers don’t answer those questions. But they do care about knowledge. Why?

5. Some Reasons… “There is only one good, knowledge” ~Socrates “Knowledge is the food of the soul” ~Plato “All men by nature desire knowledge” ~Aristotle “Knowledge is power” ~Thomas Hobbes “The only fence against the world is a thorough knowledge of it” ~John Locke

6. More Recently Recently, some philosophers have defended two other claims about the central importance of knowledge: • Knowledge is the norm of assertion. (Stanley and Williamson) • Knowledge is the norm of action. (Hawthorne and Stanley)

7. The Beginnings of Western Philosophy Western philosophy, like much of Western culture, and Western literary and artistic traditions, traces its history back to ancient Greece.

8. Thales (624-546 BCE) Thales of Miletus was the first philosopher, according to Aristotle, and is sometimes considered the first scientist (and even the first mathematician), because he tried to give natural explanations (as opposed to mythological or supernatural explanations) of things, based on general principles, which he supported with reasons and arguments (and not just things he made up).

9. Socrates (469-399 BCE) Socrates was a philosopher in Athens during a period of political turmoil. Socrates left no written work, and all that we know about his views is from dialogues written by his students Plato and Xenophon, comments by Aristotle, as well as comic plays by Aristophanes that poke fun at him.

10. The Wisest Man One day, one of Socrates’ friends Chaerephon went to the Oracle at Delphi (a prophecy speaking priestess at the temple of Apollo), and asked her whether there was anyone wiser than Socrates in all of Athens. She said ‘no.’ This surprised Socrates, because he believed he had no wisdom at all.

11. Athens’ Gadfly Socrates set out to test the Oracle’s claim by seeking out the people he thought should be wise in Athens. If he could find that they had any wisdom at all, he would know her claim was false. What he discovered by questioning all these people was that even though they claimed to know a lot, none of them knew anything. His great discovery was that he was wise, because unlike them he knew that he knew nothing.

12. The Socratic Method Socrates’ method was not to argue for or against any position (remember, he didn’t believe he knew anything), but rather to tease out other people’s beliefs through careful questioning, and then to lead them to realize that their beliefs were wrong– again, by forcing them to answer questions that they hadn’t considered.

13. Plato (424-348 BCE) Plato is often considered the greatest Western philosopher of all time (and his usual competition for #1 is his student, Aristotle). Whitehead once said, “the European philosophical tradition… consists of a series of footnotes to Plato.”

14. Plato and Socrates Plato was a young follower of Socrates. After the death of Socrates, Plato wrote dialogues where Socrates was the main character and Plato (in the few times where he was present) never spoke.

15. The Literary Socrates There are lots of reasons to suppose that the literary character Socrates who appears in Plato’s dialogues is not presenting views or arguments that Socrates presented, and over the course of Plato’s life, the views the literary Socrates expresses change and grow. But the literary Socrates is not just Plato. Aristotle says that Plato had an “unwritten doctrine”– his true beliefs– which he refused to write down.

16. Theaetetus Plato’s dialogues are named after the main character that Socrates has a discussion with in the dialogue. The Theaetetus is a dialogue in which Socrates talks with Theaetetus. Theaetetus is regarded as Plato’s best dialogue on epistemology (the theory of knowledge), and sometimes his best dialogue simpliciter.

17. Three Theories of Knowledge In the dialogue, Plato asks Theaetetus, a young Greek mathematician, and also his mentor Theodorus, another mathematician, what the essence of knowledge is: “What is knowledge?” Theaetetus proposes three theories of the essence of knowledge, and by the end of the dialogue, all of them are rejected.

18. Objectual and Propositional Knowledge In English, there are (at least) two grammatically distinct constructions involving know. Objectual knowledge, knowing a person, a thing, or a place: “I know Professor Lau.” Propositional knowledge, knowing a fact: “I know that Professor Lau has hair.”

19. French In French, for instance, different verbs are used for the different senses of ‘know’: ‘Connaître’ is used for objectual knowledge: ‘Je connaisbienToulouse’– I know Toulouse. ‘Savoir’ is used for propositional knowledge: ‘Je sais qu'il l'a fait’– I know thathedidit.

20. Possible Confusion Socrates and Theaetetus often don’t make a distinction between the different kinds of knowledge. Greek doesn’t have a strong grammatical distinction between the two kinds of ‘know’ so Socrates and Theaetetus may have thought that we needed to give one account that applied to both kinds at once (rather than treating them as different things).

21. One Non-Theory Theaetetus’ first attempt at answering the question “What is knowledge?” is to list the different kinds of things that are knowledge: Geometry is knowledge, carpentry is knowledge, animal husbandry is knowledge…

22. Essence, Not Examples This is unacceptable, because remember we want to know the essence of knowledge, not examples of knowledge. We want to know why geometry, for example, is knowledge; in virtue of what carpentry is knowledge; what makes it true that animal husbandry is knowledge, and so forth.

23. A Comparison Socrates compares Theaetetus’ proposal to a proposed definition of ‘clay’ that goes: “there’s the clay of sculptors, and the clay of potters, and the clay of brick makers…” This doesn’t help anyone who doesn’t already know what clay is. It doesn’t tell us what it is about a thing that makes that thing clay.

24. First Definition What Socrates wants is a definition of clay. If something fits the definition, then it is knowledge, and if it does not fit the definition, it is not knowledge. Theaetetus first attempt at a definition is: Knowledge = perception

25. Protagoras (490-420 BCE) Socrates thinks that this definition is close to the beliefs of Protagoras, another Greek philosopher, who was the mentor of Theodorus (Theaetetus’ mentor). Protagoras was famous for his claim that “Man is the measure of all things: of things which are, that they are, and of things which are not, that they are not”

26. Truth Relativism Protagoras’ doctrine is a version of truth relativism, the idea that there are no absolute truths, only truths relative to this person or truths relative to that person. It might feel cold to you and not cold to me; then it was true relative to you that it was cold, and not true relative to me that it was cold.

27. K = P and Truth Relativism Truth relativism is not a view about knowledge (although Protagoras and Heraclitus both held the view that knowledge = perception). The relevance here is that the claim that knowledge = perception entails truth relativism, given the principle: If you know something, then it is true.

28. Argument I might feel cold while you do not feel cold. Therefore, perception is person relative. Knowledge = perception. Therefore, knowledge is person relative. Whatever is known is true. Therefore, truth is person relative.

29. Heraclitus (535-475 BCE) Socrates, in attempt to explain how truth relativism can be made sense of, brings in some ideas of Heraclitus. Heraclitus is a mysterious philosopher whose work does not survive. He is known as believing things like ‘Everything flows’; ‘You can never step into the same river twice’; and ‘The path up is the same as the path down.’

30. Everything Flows Here’s how Socrates thinks these ideas can be employed: Nothing is ever in a fixed state of being. Instead, everything is constantly changing or becoming something else. When I perceive a thing, it becomes one thing, and when you perceive it, it becomes something else.

31. Nothing IS So there is no point in saying what a thing is, for it is never any one thing, but becomes many. And there is no point in saying what it becomes, for it becomes something for me and a different thing to you. Everything is flux, and thus perceptions of different people are always different, and so what is known is always different.

32. The Dream Objection Socrates proposes an objection to the knowledge = perception thesis. If knowledge = perception, then knowledge of existence = perception of existence. But in dreams we perceive things as real that we (when we are awake) know are not real, like dragons and monsters.

33. Nothing IS Later, Socrates recognizes that this objection doesn’t work, at least if Heraclitus is right. Nothing, including ourselves, merely is. We do not continue existing when we dream but become something else, which is also unstable and changing. Relative to that thing, the objects of dreams are true.

34. Disanalogies between Knowledge and Perception Socrates outlines some disanalogies: • Perception comes in degrees of sharpness and intensity, knowledge doesn’t. • Perception varies with distance from the object perceived, knowledge doesn’t. • You can see something and not hear it (perceive it and not perceive it) but not know something and not know that thing.

35. We’re All Equal Knowers And he makes three points about what knowledge = perception entails: • Animals are just as knowledgeable as humans, what they perceive is true for them. • Humans are just as knowledgeable as gods, for both perceive their own truth. • Protagoras is just as knowledgeable as any man off the street.

36. Why Are Relativists Philosophers? Of course, Protagoras is not going to deny either (1) or (2). His theory commits him to those beliefs, and there’s nothing contradictory with holding them. But if he also believes (3), why does he teach philosophy? If everyone already knows what’s true-for-them, what can they possibly gain by listening to him?

37. Protagoras Responds Socrates imagines a response: the purpose of philosophy is not to give people truth who believe falsehoods, because everyone has what’s true for him. The purpose of philosophy is therapeutic: for some people, what’s true is awful, because what they believe is awful. The philosopher’s goal is to make what they believe good, and thus what is true-for-them good.

38. Absolute Goodness, Relative Truth The response involves accepting an absolutism about what is good or beneficial (even while it maintains a relativism about truth). If what is beneficial is relative, then changing the beliefs of others is only good relative to some philosophers, while it is bad relative to other philosophers.

39. The Real Protagoras Protagoras actually did hold the view (when he was alive) that benefit was absolute, while truth was relative. There are some reasons to go this way. If benefit was relative, then suppose you thought it would help you get an A (benefit your goals) to drink beer and not study. Then relative to you, that would help. But that’s absurd!

40. Contradiction? Suppose that it is absolutely beneficial to believe in truth relativism (TR). Then relative to anyone, it is beneficial to believe in TR. But someone could believe that it is not beneficial to believe in TR. This belief would be true for that person. So relative to them, belief in TR is not beneficial.

41. A Second Contradiction? TR says that truth is absolutely relative: truth is relative to every individual person. But clearly someone could believe that TR is not true. Then according to TR, that belief is true-for-them. So relative to them, TR is not true. So TR is not true of some people.

42. Final Objection to Protagoras Protagoras seems to have a problem with the future. If what I believe to be true is true for me, then my beliefs about the future are true for me. So suppose I believe that Tuesday. I’ll win the lottery; then it’s true for me that I’ll win Tues. But when Tuesday. rolls around, I don’t win. Now it’s true for me that I don’t win on Tuesday.

43. Summary: Argument against Protagoras • Knowledge and perception are disanalogous in many ways. • K = P entails truth-relativism (TR): if we believe it, it’s true-for-us. • TR entails the relativity of goodness or benefit. • TR is self-contradictory or self-defeating. • TR is incompatible with the intuitive fact that we can believe false things about the future.

44. Final Objection to Heraclitus According to the theory of Heraclitus, everything flows, and is constantly changing. This means, for example, that white things are always changing to different colored things. But it must also mean that knowledge flows and is constantly changing. So we shouldn’t say: knowledge = perception, because it will change and ≠ perception.

45. Final Objection to K = P There are some things that we know, that are not things we can perceive. • Sameness and difference: we know our seeings are different from our hearings, but we don’t perceive this, because none of the senses both sees and hears. • We know mathematical truths, but we don’t perceive “all triangles have 3 sides.”

46. Final Objection Continued 3. Good and evil: you can see an action, but you cannot see that it is good. However, you can know that some things are good. 4. Essences: if it were possible to perceive what the essence of knowledge is, then we wouldn’t need to do philosophy. We’d just need to look for, or smell, or taste the right answer. But we assume we can know the essence.

47. Definition Number 2! After all that, Theaetetus is now asked if knowledge is not the same as perception, what is knowledge? Theaetetus makes a new proposal: Knowledge = true belief

48. The Main Issue If knowledge = true belief, then since some beliefs we have are known and other beliefs we have are not known, there must be a distinction between true and false beliefs. The main issue that Socrates is concerned with is how are false beliefs possible?

49. Anything I Can Think, I Know If I don't know a thing, I can't think about it. So, if I can think about it, I know it. If I know it, I know its essence. If I know its essence, I can't be wrong about it. So anything I can think about, I have only true beliefs about. Therefore, I cannot have false beliefs.

50. Faulty Premise The most natural place to find an error in this argument is in the premise that if you know the essence of a thing, you can’t be wrong about it. I can know for example, that goodness = what the gods love, but not know that helping others is good, because I don’t know if the gods love helping others.