PHIL105: The Big Questions

1. PHIL105:The Big Questions Trimester 3 - 2011

2. What is Philosophy? • Using reason & rational argument to answer the big questions • The big questions are: • The very important ones • Hard to answer even when we have all or most of the relevant facts

3. Topics • Week 1: Personal identity • Week 2: The good life • Week 3: The meaning of life Dan

4. Introduction to Personal Identity PHIL105 – T3, 2011 Lecture 1

5. Personal Identity • Who am I? • What makes me the same person through time? • What happens to me if I’m copied? • What about people who have their brains chopped in half!?! • Hard questions, even if we have all of the facts

6. Terminology • Numerical identity • A (literally) unique thing • Qualitative identity • Looks, feels, tastes (etc) identical • Essential properties • Required for numerical identity • Accidental properties • Can change without affecting numerical identity

7. Personal Identity & the Afterlife • It can comfort us to think that our loved ones live on somehow after death • But what would that really entail?

8. Reincarnation • You are reborn into a new body after death • PROBLEM: Reincarnations don’t seem to be the same person

9. Resurrection • You (and your body) come back to life after you die • PROBLEMS: • Need an earth-like place to go to • If we’re recreated exactly the same, we’ll just die again • Some of your atoms will be part of other organisms

10. Soul Liberation • When we die, our soul leaves our body to live on somewhere else • PROBLEMS: • What, exactly, is a soul? • What would your soul be like? • Is a soul just the hard drive that our memories, beliefs, and personality are written on to? • Is your soul without your body really you?

11. Cryogenics • Being frozen until medical advances can fix all your ailments • PROBLEMS: • Technological risk • The brain may be too damaged • Ice-cream headache

12. Cyborgs • Use technology to keep us alive! • PROBLEMS: • Will it ever work? • How will we know?

13. Personal Identity & the Accident Victim • Brain damage and amnesia could drastically change what a person is like • But, would it change who they are?

14. COMINS • Continuity of the Mental Is Necessary for Survival • VERDICT: Mr Edward’s son has not survived the accident • PROBLEM: • How much and what type of ‘the mental’ has to continue and how must it continue?

15. CEBINS • Continued Existence of the Body Is Necessary for Survival • VERDICT: Mr Edward’s son has survived the accident • PROBLEM: • This may be necessary, but is it sufficient for a person to survive?

16. CESINS • Continued Existence of the Soul Is Necessary for Survival • VERDICT: Mr Edward’s son has survived the accident • PROBLEM: • If it’s not the body or the mental… what, exactly, is the soul again?

17. Summary – What Makes Us Survive? • Continuation of mental • Continuation of body • Continuation of soul • A combination • Has Martha’s Mum survived? • Has Edwards’ son survived? • Maybe we don’t survive?

18. Philosophy Clinic:How to Argue that a Theory is the Best Theory • Explain the main theories and their main strength • Apply the theories to real and whacky examples • A good theory will give an answer in each case (who is the same person?) • The best theory will give the right answer for a good reason in most of the cases • Good reasons for right answers are generally consistent with our reflected-upon intuitions • But you can also explain why some particular intuitions are wrong (and your theory is right)

19. The elusive ‘I’ • Who here thinks they exist? • Cogito ergo sum • Meditation time!!?? • Lets ‘find ourselves’ • Where am ‘I’ ?!?!

20. For Next Time • Read: • Law, Stephen: Brain Transplants, ‘Teleportation’ and the Puzzle of Personal Identity • Parfit, Derek: Divided Minds and the Nature of Persons

21. More on Personal Identity PHIL105 – T3, 2011 Lecture 2

22. Personal Identity • We want our theory to provide answers to questions like these: • What makes me me? • What makes me the same person through time?

23. Terminology • Numerical identity • A (literally) unique thing • Qualitative identity • Looks, feels, tastes (etc) identical • Essential properties • Required for numerical identity • Accidental properties • Can change without affecting numerical identity

24. Sci-Fi Disclaimer • The following ‘whacky’ thought experiments may never be possible in real life • But, then again, they might! • Regardless, a good theory of personal identity should be able to answer theoretically possible as well as actually possible problem cases

25. Animal Theory • In essence, each person is a living animal • What essentially makes me me through time is that I am the very same living creature as the one in the photos

26. Brain Transplant Case • A brother and sister have their brains swapped while they sleep one night • Problem for the Animal Theory

27. Brain Theory • In essence, each person is their unique living brain • What essentially makes me me through time is that I have the very same brain as the ‘me’s in the photos

28. Brain Recorder Case • This device re-splices the existing brain bits so that a pre-recorded personality (etc) can be downloaded into the (same) old brain • Problem for the Brain Theory

29. Stream Theory • AKA: Psychological Continuity Theory • In essence, each person is (the right kind of) continuation of psychological properties • E.g. What MIGHT essentially makes me me through time is that my memories are psychologically continuous

30. The Reduplication Case • This device makes perfect copies of anything put in cubicle A (in c. B) but the original is vaporized • A new model also makes a duplicate in cubicle C • Problem for the Stream Theory?

31. Modified Stream Theory • In essence, each person is (the right kind of) continuation of psychological properties • Except when two or more people are psychologically continuous (in the right kind of way) from one person • In which case, none of those later people are the same person as the original person

32. The Duplicator Gun Case • This device makes a perfect copy of anything shot with it but it doesn’t destroy the primary target • Problem for the Modified Stream Theory

33. They All Seem Wrong! • The Animal Theory • Gets the brain transplant and recorder cases wrong • The Brain theory • Gets the brain recorder case wrong • The Stream Theory (AKA the Psychological Continuity Theory) • Gets the reduplication and duplicator gun cases wrong • The Modified Stream Theory • Gets the duplicator gun cases wrong

34. The Teletransporter Case • You have been ‘teletransporting’ to work (on a very distant planet) for 3 years • You are at work when you are informed that the ‘teletransporter’ really works like the reduplicator (it copies & kills you) • Do you get in and ‘teletransport’ home? Why? Why not?

35. Divided Minds and the Nature of Persons • Derek Parfit • Split-brain cases tell us something interesting about personal identity • There are no ‘persons’ in a split-brain case • But there were no ‘persons’ before the brain was split either

36. Why Chop Your Brain in Half? • Suffers of severe epilepsy had their corpus callosum chopped in half to prevent seizures spreading across hemispheres • This means that the two halfs of the brain cannot communicate directly with each other • The resulting body acts as normal in most cases and suffers from less debilitating seizures

37. The Experiments • Left hemisphere controls right eye & hand (& speech in right-handers) • Using a special technique, each hemisphere was exposed to a different stimuli • Each hand responded as though there is a separate stream of consciousness in each hemisphere

38. How Visual Fields Really Work

39. More Info on the Actual Split-Brain Experiments • A picture is flashed in the left visual field (for a right-hander) so fast that the right eye can’t see it, but the left eye can. • When asked, the person says they couldn’t see the picture • But the ‘locked-in’ right hemisphere did see it!

40. What ‘Goes With’ What? • When asked to point to the picture that ‘goes with’ what they see… • Each hand goes for a different picture!

41. Does Each Hemisphere Know about the Other One? • They seem to ignore or be unaware of each other • Before the op. patients can name objects on both sides, but only on one side after the op. • Interestingly, they don’t complain about the loss

42. The Ego Theory • What essentially makes me me through time is that all of the ‘me’s are the same subject of experiences (ego) • What unites the many experiences I have had in my life is that I was the one having them all • The Cartesian View is an example of this (my ego is my soul)

43. The Bundle Theory • We cannot explain our survival through time by referring to a ‘person’ • Because no ‘person’ (subject of our experiences) exists! • There are just bundles of mental states (experiences) tied together by the causal relation of memory (experiencing remembering previous experiences) • We call these bundles ‘lives’

44. The No Self View • Buddha was the first bundle theorist • His No Self View is a type of bundle theory • People have ‘nominal existence’ (we sometimes talk as if they exist), but only the parts that make them up really exist

45. Parfit: What We Believe Ourselves to Be • Science tells us that: • There is no evidence for the Ego Theory • There is evidence for the Bundle Theory • Most of us believe something like the Ego Theory to be true • Unfortunately, most of us hold false beliefs about who we are! • Me: But does science tell us that?

46. Replacing Your Cells Case • A high-tech alien is going to replace some of your cells with identical replicas (all at once) • If it changes 1% of your cells, are you the same person? • What if it changes 100% of your cells? • There are answers to these qns

47. How We are Not What We Believe • How could we even know if 49% or 50% (or whatever) replaced cells is the right place for the line? • It is implausible that a few cells will make the difference in the Replacing Your Cells Case • But that is what our natural beliefs/intuitions force us to say! • Therefore, we should embrace the Bundle Theory

48. Bundle Theory Applied • When applied to all of the cases, the Bundle theory rejects the question, ‘what happens to you?’ • The Bundle Theory can explain what happens, but it doesn't refer to persons (because they don’t really exist) • If ‘50% of your cells are replaced,’ then 50% of that bodies cells are replaced • You don’t end or survive because you were never there in the first place! • These cases only raise worries because we don’t properly understand the nature of persons

49. PARFIT: Split-Brain Cases and the Ego Theory • The Ego Theory says that all of the experiences in the split-brain case are being had by the one ego/person (but in 2 streams) • The Ego Theory is wrong because it ignores the disunity between the two streams of consciousness • The ego can’t just split in two • Because it is supposed to be the one unique persisting essential element of a person

50. PARFIT: Split-Brain Cases and the Bundle Theory • On the Bundle Theory, bodies normally have an awareness of having several different experiences at any one time • There is no ‘I’ (an independently existing & persisting thing) required for the explanation • In the split-brain case, there are two separate states of awareness of experiences • But neither of those states is a unique, independently existing & persisting ‘I’ (they don’t exist)