1. The Causal Historical Theory

2. Natural Kinds Kripke and another philosopher Hilary Putnam wanted to generalize what was true of names to “natural kind terms” (a phrase introduced by Quine).

4. The Causal-Historical Theory Let’s call that thing a “tiger.” TIGER

5. Ignorance: Water In Hilary Putnam’s classic “The Meaning of ‘Meaning’” he argues that “meaning just ain’t in the head.” In particular, he presents his famous Twin Earth thought experiment, which is intended to show that what the word ‘water’ is true of is not determined by what we know or believe about water.

6. Twin Earth Twin Earth is a planet on the other side of the galaxy. In most ways, it is just like Earth, down to the smallest detail. You have a twin on Twin Earth who’s just like you, I have a twin who’s just like me, they’re sitting in a twin classroom, and my twin is giving a lecture just like this one to your twin. And so on and so forth.

7. EarthTwin Earth

8. There is however one difference between Earth and Twin Earth. On Earth, all the watery stuff is H 2 O. On Twin Earth, the watery stuff is composed of a complicated chemical compound we can abbreviate XYZ. H 2 O and XYZ look and behave exactly the same. They taste the same, they boil at the same temperatures at the same distance above sea level, their conductance is the same, etc.

9. Twin Earth Consider two twins, Arnold on Earth and Twin Arnold on Twin Earth. Neither knows any chemistry. What they know/ believe about the stuff they call ‘water’ is the same. Q: Would it be true for Arnold to call the stuff on Twin Earth ‘water’?

10. Strange Circumstances Philosophical thought experiments: controlling for confounds Real life cases are messy: fool’s gold Why does what we say matter for how to interpret Oscar and Twin Oscar?

11. A Common Principle Principle: Whenever we have some object O to which speakers apply some term T, then a good guide to whether T does in fact apply to O is to ask whether those speakers would persist in applying T to O when they were set right about their mistaken beliefs (if any) regarding O.

12. Error: Gold Kant thought that the definition of gold was ‘yellow metal.’ This is the description that determines what things count as ‘gold.’ Kripke asks, “Could we discover that gold was not in fact yellow?” p. 118.

13. Kripke Invokes the Principle Suppose there were an optical illusion that made the substance appear to be yellow; but, in fact, once the peculiarities of the atmosphere were removed, we would see that it was actually blue…

14. Kripke Invokes the Principle Would there on this basis be an announcement in the newspapers: ‘It has turned out that there is no gold. Gold does not exist. What we took be gold is not in fact gold.’?... It seems to me that there would be no such announcement. [1980 p. 118]

15. Putnam’s Theory Putnam thought that ‘water’ named the substance around here that falls from the skies, flows in lakes, rivers, and streams, quenches thirst, etc. The substance around Oscar is different from the substance around Twin Oscar, so ‘water’ meant different things to each of them.

16. Other Kinds of Kind Terms

17. Michael Johnson 1982- American/ Hong Kong philosopher

18. Natural Kinds One common view in philosophy is that natural kinds are kinds that are individuated by their “microphysical structure”. (The substance around here.)

19. Surface reflectance DNACharged particles Chemical composition

20. Other Kinds of Kinds But what about kinds that are individuated: By what causes them. (Etiological kinds) By what they are for. (Teleological kinds) For arbitrary or human-centric reasons

21. Etiological Kinds

22. Schiaparelli The year is 1877 and Mars is in opposition. Giovanni Schiaparelli, the Italian astronomer, takes the opportunity to carefully examine the red planet via telescope. What he observes is a set of roughly straight lines criss- crossing the planet, which he dubs canali.‘

23. Canali

24. Schiaparelli Several theories are defended in subsequent years. Some think that the canali are natural formations caused in a certain way, say, by the flow of liquid water along the planet‘s surface. Others think that they are literally canals dug by agents who inhabited or once inhabited Mars.

25. What does ‘Canali’ mean? “That type of thing over there, whatever it is.”

26. Teleological Kinds

28. Potential Case: Hearts Fred lives in the 2 nd Century C.E. If asked to state everything he believed about hearts (which he calls ‘καρδιά’), he would say: They are the seat of the soul Their purpose is to create some but not all of the blood in the body (bright blood as opposed to dark blood) They are red in color They are shaped roughly like contemporary Valentine‘s day cards

29. Error: Hearts Quite unknown to Fred and his contemporaries, none of his beliefs regarding hearts is true. The seat of the soul is the pineal gland hearts pump blood, but do not create it They are green (but appear red because of an atmospheric illusion) They are not what we now call heart-shaped

30. A Common Principle We may now ask, echoing Kripke: suppose that Fred‘s errors were discovered to him and his community. Would there on this basis be an announcement in the forum: ‘It has turned out that there are no hearts. Hearts do not exist. What we took to be hearts were not in fact hearts.’? It seems that there would be no such announcement.

31. Michael’s View “heart” names things with the same function of those things around here.

32. Human/ Arbitrary Divisions

33. Tiny Earth Tiny Earth is a planet on the other side of the galaxy. In most ways, it is just like Earth, down to the smallest detail. You have a twin on Tiny Earth who’s just like you, I have a twin who’s just like me, they’re sitting in a twin classroom, and my twin is giving a lecture just like this one to your twin. And so on and so forth.

34. EarthTiny Earth

35. Twin Earth There is however one difference between Earth and Tiny Earth. On Earth, everything is 1000x bigger. Everything looks and behaves exactly the same. It’s just bigger on Earth.

36. MMNS

37. Machery, Mallon, Nichols & Stich In their highly influential 2004 paper “Semantics, Cross-Cultural Style,” MMNS claim to uncover evidence that while Westerners have intuitions that accord with Kripke and Putnam (that is for causal- historical theories and against descriptivism), East Asians have (on average) more descriptivist intuitions. For example, they think in the Twin Earth case, XYZ is water. According to MMNS!

38. MMNS I am personally weary of the methodology, and I find it a little bit silly to think that anyone, East Asian or not, thinks that Americans who only believe about Neil Armstrong that he was the first man in space, speak truly when they say “Neil Armstrong was the first man in space.” [Descriptivist says TRUE because Yuri Gagarin satisfies description, hence “Neal Armstrong” means Yuri Gagarin, and it’s true that Yuri Gagarin was the first man in space!]

39. MMNS Still, this is another important reminder that the subjects of philosophy discussion cannot always be resolved by philosophers (at least, philosophers who don’t have labs and test subjects). Sometimes philosophical questions are empirical, and can’t be solved solely through debate.