Time, Self and Mind (ATS1835) Introduc on to Philosophy B Semester 2, 2017 Dr Ron Gallagher [email protected] Week 10 (1 le ): Knowledge (Epistemology) & Scep cism
What is knowledge? What is jus fed true belief? What is scep cism? What is doubt? What is jus fica on? Can any knowledge be jus fied? Can ordinarily accepted statements be jus fied? Radical doubt is nonsensical, selec ve doubt needs grounds for doubt.
Week Beginning Topic Assessment Readings W1 24-Jul Time - Introduction and Time Travel 1.1 & 1.2 Time Travel; Freedom, Determinism, and W2 31-Jul Indeterminism 1.5 & 1.6 Short Answer 1 - W3 07-Aug Logic Primer August 10th 2.1 – 2.2 Mind- Dualism versus Materialism about W4 14-Aug the Mind 3.1 - 3.2 Mind - Can Machines Think? W5 21-Aug Computationalism and the Turing Test 3.3
Mind - Can Machines Think? Objections to Short Answer 2 - 3.4 W6 28-Aug Computationalism Aug 31st Self - Lockean Psychological Theory and W7 04-Sep Identity 4.1 – 4.3 W8 11-Sep Self - Identity, the Body & Person Stages 4.4 – 4.5 Knowledge What is Knowledge and Short Answer 3 – W9 18-Sep Gettier's Account Sep 21st 5.1 – 5.2 25-Sep Mid-semester break Knowledge - Nozick's Account and 5.3 – 5.4 W10 02-Oct Scepticism Essay - October 5.5 W11 09-Oct Knowledge - The Moorean Response 12th W12 16-Oct Revision (no lectures, no tutorials) Assessment
Due Date Assessment Task Value Mondays 10am Reading Quizzes (10) 5% (bonus) Thu Aug 10th AT1.1 (@600 words) 10% Thu Aug 31st AT1.2 (@600 words) 10% Thu Sep 21st AT1.3 (@600 words) 10% Thu Oct 12th AT2 Essay (@1250 words) 30% TBA Exam 40% Hurdle Requirements to Pass this Unit Your overall grade for the unit must be at least 50% You must achieve a grade of 40% or more on the final exam You must submit all assessment tasks (not including Reading Quizzes) You must not fail more than one assessment task (not including Reading Quizzes) You cannot miss more than 3 tutorials AT2: Essay Assignment (Due: October 12th, 10am) General Instructions Word Limit: 1250 words Value: 30% Presentation Requirements: Your assignment should be presented in 12-point font and 1.5 or double-spaced. It will require references and a bibliography. Acceptable Formats: .doc or .rtf. (If you want to use some other format, clear it with your tutor beforehand.) Only submit an electronic copy; no hard copy submission required. File Name: Name your file using the following convention: [Question Number] [Surname] Example: "3Silva.doc," "5Smith.rtf", "1Jones.docx" Referencing and Citation: http://artsonline.monash.edu.au/philosophy/resources-for- undergraduate-students/ In your essay, you should try to fulfill the following requirements, especially the first: • The essay must address the question asked. • It should have a structure that is clear and organised to form a coherent argument. • You should explain, in your own words, views and arguments in the prescribed readings that are relevant to the topic. Be careful to present these views fairly and accurately, with adequate citation detail. • You should try to evaluate the arguments you have discussed, and in the process work out your own position. When you criticise a philosopher, try to think how she might reply to your objections. • You must carefully identify all connections between your essay and the writings of others.
Chicago style (numerical citation, footnotes) with bibliography at the end.
Harvard style (in-text citation) with bibliography at the end. ESSAY MARKING CRITERIA - from ATS1835 Unit Guide ESSAY FAQs • Essay Due Thursday 12th October 10am @1250 words 30%
• The word limit is +/- 10% of 1250 words.
• You are required to use at least one of the readings (not just the commentary or lecture slides) from the TSM Reader as your primary text.
• You can reference the TSM Reader by page number, eg (Kane, 2007,TSM Reader p.56), you do not need to use the original page numbers of the individual papers in the Reader.
• Begin the essay with a statement of YOUR thesis (eg You believe that machines do not think, and that Turing is wrong for such and such a reason and that Searle makes some good points) and how you are going to support it with arguments from the TSM Reader
Essay Topics Write on one of the following topics. AT2 Essay - Thursday Oct 12th, 10am - @1250 words – 30%
5. Knowledge Gettier raises some serious challenges for the traditional account of knowledge. Nozick develops his tracking account in part to answer the problems identified by Gettier. After explaining both Gettier's challenge and Nozick's proposal, evaluate the strength of Nozick's proposal as a response to Gettier's challenge.
Required reading: Edmund Gettier, 'Is Justified True Belief Knowledge?' Robert Nozick, 'Knowledge and Skepticism' 1. Knowledge as Justified True Belief There are three components to the traditional (“tripartite”) analysis of knowledge. According to this analysis, justified, true belief is necessary and sufficient for knowledge. The Tripartite Analysis of Knowledge: S knows that p iff p is true; S believes that p; S is justified in believing that p.
The tripartite analysis of knowledge is often abbreviated as the “JTB” analysis, for “justified true belief”. From http://plato.stanford.edu/entries/knowledge-analysis/index.html
JTB?
Derelict Juror: Imagine two Stubborn Evolu onist: Henry jurors, Jenna and Na lie, has been exposed to a number delibera ng about the case of of ra onally compelling Mr. Mansour. Both jurors have arguments for the theory of paid close a en on throughout evolu on. Despite the trial. As a result, both have understanding these arguments, Henry refuses to accept good reason to believe that [evolu on], through sheer Mansour is guilty. Each juror stubbornness. One day, Henry’s goes on to form the belief that tarot card reader tells him that, Mansour is guilty, which he in based on a recent tarot reading, fact is. Na lie believes he’s she has determined that the guilty because of the evidence theory of evolu on is true. presented during the trial. Jenna Henry then finally accepts believes he’s guilty because he evolu on on the basis of the looks suspicious. tarot reading.
QUESTION: Does Harry know QUESTION: Does Jenna know that evolu on is true? that Mansour is guilty? The Basing Demand
General Issue: – S can have terrific evidence to think P true. – S can believe P is true. – But S can fail to believe P because of the evidence. = S can fail to base her belief in P on the evidence. = S can believe P for obviously irrelevant reasons. The Basing Demand: In order to know P one must have a jus fied belief in P. In order to have a jus fied belief one must base that belief on good reasons. Epistemic Luck (Russell)
Alice sees a clock that reads two o’clock, and believes that the time is two o’clock. It is in fact two o'clock. There's a problem, however: unknown to Alice, the clock she’s looking at stopped twelve hours ago. Alice thus has an accidentally true, justified belief. Russell 3. The Gettier Problem In his short 1963 paper, “Is Justified True Belief Knowledge?”, Edmund Gettier presented two effective counterexamples to the JTB analysis (Gettier 1963). One of these goes as follows. Suppose Smith has good evidence for the false proposition (1)Jones owns a Ford. Suppose further Smith infers from (1) the following three disjunctions: (2)Either Jones owns a Ford or Brown is in Boston. (3)Either Jones owns a Ford or Brown is in Barcelona. (4)Either Jones owns a Ford or Brown is in Brest-Litovsk. Since (1) entails each of the propositions (2) through (4), and since Smith recognizes these entailments, his beliefs in propositions (2)–(4) are justified. Now suppose that, by sheer coincidence, Brown is indeed in Barcelona. Given these assumptions, we may say that Smith, when he believes (3), holds a justified true belief. However, is Smith's belief an instance of knowledge? Intuitively, Smith's belief cannot be knowledge; it is merely lucky that it is true. In the first example, Gettier supposes that two people, Smith and Jones, have applied for a job. We suppose that Smith has a justified belief that Jones will get the job. The evidence for it is high enough that Smith justifiably believes it, “might be that the president of the company assured him that Jones would in the end be selected” Smith also believes (and indeed, knows) that Jones has ten coins in his pocket, which is true and was demonstrated to him, possibly by Jones counting them himself. From this he believes the logical conseqence of these beliefs, that “the man who will get the job has ten coins in his pocket”¹ It turns out that Smith was wrong, and that, for some unforseeable reason, it turns out that Smith gets the job, and Jones does not. It also turns out that Smith has ten coins in his pocket, though he didn't realize it. The question is, was Smith's belief that “the man who will get the job has ten coins in his pocket” knowledge?
Gettier and Propositional Knowledge
Gettier argues that one could have a true justified belief which is not knowledge in a situation in which one reasons from some already justified beliefs to a new belief that, as it happens, is coincidentally true. Since it would then be a matter of coincidence that one’s belief was correct, it would not count as knowledge, even though it was a justified belief because it was knowingly inferred from already justified beliefs.
Most epistemologists have accepted Gettier's argument, taking it to show that the three conditions of the JTB account—truth, belief, and justification—are not in general sufficient for knowledge. How must the analysis of knowledge be modified to make it immune to cases like the one we just considered? This is what is commonly referred to as the “Gettier problem”. Above, we noted that one role of the justification is to rule out lucky guesses as cases of knowledge. A lesson of the Gettier problem is that it appears that even true beliefs that are justified can nevertheless be epistemically lucky in a way inconsistent with knowledge. Epistemologists who think that the JTB approach is basically on the right track must choose between two different strategies for solving the Gettier problem
From http://plato.stanford.edu/entries/knowledge-analysis/index.html
Structure of the Counterexample Reminder: Tradi onal account says JTB is necessary & sufficient for knowledge. Ques on: What does this counterexample teach us about the JTB account of knowledge? JTB is… (a) Not necessary for knowledge. (b) Not sufficient for knowledge. (c) Neither necessary nor sufficient for knowledge.
Structure of the Counterexample: S has JTB But: S doesn’t know that p So: JTB is insufficient for knowledge
How to Proceed: S knows that p iff JTB + ? Any guesses as to what should be added?
21
Traditional JTB Nozick’s Conditions p is true; 1. p is true. S believes that p; 2. S believes p. S is justified in 3. If p were false, S would not believe p. believing that p. 4. If p were true, S would believe p. The Sheep Case (NTA): S knows that p only iff: 1. p is true. 2. S believes p. 3. If p were not true, then S would not believe p. 4. If p were true, S would believe p.
Ques on: Is condi on 3 sa sfied in the Sheep Case? That is, is the following true:
(A) If there were no sheep in the field, S would not believe that there are sheep in the field.
NO! I.e., S would s ll believe it. –So condi on 3 is not sa sfied. –So according to Nozick’s theory, one does not know that there is a sheep in the field. This is exactly the conclusion we want.
Nozick (sensitivity conditions)
S knows that p when the following conditions hold: 1. p is true. 2. S believes p. 3. If p were false, S would not believe p. 4. If p were true, S would believe p.
This new formulation of justified true belief should expose cases of ‘epistemic luck’ as not knowledge. That is, Gettier-style ‘counterexamples’ should be exposed by this fomulation, with two test conditions, as not knowledge.
Nozick (sensitivity conditions) Does Alice know it is 2 O’Clock?
Alice knows that it is 2 O’Clock iff: 1. It is true that it is 2 O’clock. 2. Alice believes 2 O’clock. 3. If it were not 2 O’Clock, Alice would not believe it. 4. If were 2 O’Clock, Alice would believe it.
It fails on 3 because Alice believes her watch and it always reads 2. Is Smith’s knowledge really knowledge? Nozick (sensitivity conditions) Smith knows that the man who will get the job has ten coins in his pocket iff: 1. The man who will get the job has ten coins in his pocket is true. 2. Smith believes the man who will get the job has ten coins in his pocket. 3. If it were false that the man who will get the job has ten coins in his pocket, Smith would not believe it. 4. If it were true the man who will get the job has ten coins in his pocket, Smith would believe it. It fails on 3 because Smith has been told that Jones will get the job and he knows he has 10 coins in his pocket. He would therefore believe it even if it wasn’t true.
Essay Topics Due Monday 12th October 10am @1250 words 30% Write on one of the following topics. 1. Time Travel How can David Lewis's solution to the Grandfather paradox be used to solve the problem of the logically pernicious self-inhibitor discussed in your Unit Reader? Be sure to clearly lay out the problem and the solution to the grandfather paradox, and to draw the parallels between that paradox and the logically pernicious self-inhibitor problem. Discuss whether the solution to this problem seems as plausible as the solution to the Grandfather paradox. Required reading: David Lewis, 'The Paradoxes of Time Travel’
The Logically Pernicious Self‐inhibiter If time travel is possible, it must be possible to build ‘a logically pernicious self inhibiter’. Here is an example devised by John Earman: Imagine a rocket ship that can fire a probe into its own recent past. Suppose the rocket is programmed to fire the probe unless a safety switch is set to on, and that the safety switch is turned on if and only if the rocket detects the return of the probe. The rocket will fire the probe if and only if it does not fire the probe. That is impossible. (TSM Reader Page 10) That is: it can fire the probe and it can’t fire the probe.
Earman asks us to consider a rocket ship that at some space-time point x can fire a probe that will travel along a timelike loop into the past lobe of x's light cone. Suppose the rocket is programmed to fire the probe unless a safety switch is on and the safety switch is turned on if and only if the "return" of the probe is detected by a sensing device with which the rocket is equipped (230-232). Is the probe fired or not? The answer is that it is fired if and only if it is not fired, which is logically absurd.This contradiction does not suffice to show that time travel per se is impossible. Rather the whole situation is impossible, and this includes assumptions about the programming of the rocket, the safety switch, the sensing device, and so forth. But, although the contradiction could be avoided by giving up some of these assumptions, Earman suggests that we have good evidence that rockets can be so programmed. Earman concludes, "Thus, although we cannot exclude closed timelike lines on logical grounds, we do have empirical reasons for believing that they do not exist in our world" (232). http://www.reasonablefaith.org/tachyons-time-travel-and-divine- omniscience#ixzz3E7PIvINl Earman, John (1972) Implications of causal propagation outside the null cone. Australasian Journal of Philosophy, 50 (3). pp. 222-237. ISSN 0004-8402
http://www.reasonablefaith.org/tachyons-time-travel-and-divine-omniscience Essay Topics..continued 2. Free Will Option 2 a): Soft determinists say free will is compatible with determinism, hard determinists deny this. Explain why soft determinists think free will is compatible with determinism and why hard determinists object to this. Which view do think is most plausible? Give your own examples that help illustrate/justify your points. Explain your reasons. Required reading David Lewis, 'The Paradoxes of time Travel' Richard Taylor, 'Freedom, Determinism and Fate' Option 2 b): Some hold that free will is (a) not only incompatible with determinism but (b) also incompatible with indeterminism. Explain this objection and explain how Kane addresses (b). Evaluate Kane's position. Do you think his view allows for people to have genuine control over and to be genuinely responsible for their actions? Give your own examples that help illustrate/justify your points. Required reading: Kane, ‘Libertarianism’
Soft Determinism vs Compatibilism
“There are compatibilists who are agnostic about the truth or falsity of determinism, so a compatibilist need not be a soft determinist (someone who believes that it is in fact the case that determinism is true and we have free will). But all compatibilists believe that it is at least possible that determinism is true and we have free will. So all compatibilists are committed to the claim that there are deterministic worlds that are free will worlds.” Kadri Vihvelin, “Arguments for Incompatibilism http://plato.stanford.edu/entries/compatibilism/ http://plato.stanford.edu/entries/incompatibilism- arguments/ See also https://yandoo.wordpress.com/2013/10/25/determinism- free-will-and-compatibilism/
Richard Taylor writes: A determinist is simply, if he is consistent, a fatalist about everything; or at least, he should be. For the essential idea that a man would be expressing by saying that his attitude was one of fatalism with respect to this or that event—his own death, for instance—is that it is not up to him whether, or when or where this event will occur, that it is not within his control. But the theory of determinism, as we have seen, once it is clearly spelled out and not hedged about with unresolved “ifs”, entails that this is true of everything that ever happens, that it is never really up to any man what he does or what he becomes, and that nothing ever can happen, except what does in fact happen. He goes on to say that fatalism should lead to resignation: A fatalist is best thought of, quite simply, as someone who thinks he cannot do anything about the future. He think it is not up to him what will happen next year, tomorrow, or the very next moment. He thinks that even his own behaviour is not in the least within his power, any more than the motion of distant heavenly bodies, the events of remote history, or the political developments in faraway countries. He supposes, accordingly, that it is pointless for him to deliberate about anything, for aman deliberates only about those future things he believes to be within his power to do and forego. Taylor, Richard, Metaphysics, 1974 (Englewood Cliffs NJ: Prentice Hall). http://andrewmbailey.com/pvi/How_to_Think_About_Free_Will.pdf “How to Think about the Problem of Free Will” by Peter van Inwagen, Journal of Ethics, (2008), 12:327–341 http://www.informationphilosopher.com/solutions/philosophers/ lewis/Are_we_free_to_break_laws.pdf ”Are we free to break the laws?” David Lewis, Theora 47, (1981), pp 112-21
TIP: be clear about your terminology – eg say exactly what you define free will, determinism and compatibilism to be. 3. Thinking Machines On the question whether machines can think, Descartes and Turing are in strong disagreement. Evaluate the arguments on either side. Does Searle's 'Chinese Room' argument help resolve the debate?
Required reading: Alan Turing, 'Computing Machinery and Intelligence' John Searle, 'Minds, Brains and Programs' (Quotes from Descartes can be found in the Notes to Part 3 of the Study Guide.)
How does Descartes’ argue against thinking machines? How does Turing’s argue for thinking machines? How does Searle argue against thinking machines?
TIP Don’t confuse thinking, intelligence and consciousness (or syntax, semantics, understanding and intentionality).
The Argument from Consciousness – Turing p 35
Professor Jefferson’s Lister Oration for 1949, from which I quote. ‘Not until a machine can write a sonnet or compose a concerto because of thoughts and emotions felt, and not by the chance fall of symbols, could we agree that machine equals brain -- that is, not only write it but know that it had written it.’ This argument appears to be a denial of the validity of our test. According to the most extreme form of this view the only way by which one could be sure that a machine thinks is to be the machine and to feel oneself thinking. One could then describe these feelings to the world, but of course no one would be justified in taking any notice. Likewise according to this view the only way to know that a man thinks is to be that particular man. It is in fact the solipsist point of view. It may be the most logical view to hold but it makes communication of ideas difficult. A is liable to believe ‘A thinks but B does not’ while B believes ‘B thinks but A does not.’ Instead of arguing continually over this point it is usual to have the polite convention that everyone thinks.
Do you accept premise 3? “Syntax is not sufficient for semantics.” Maybe Haugeland is right. “If you take care of the syntax, the semantics will take care of itself.” (Haugeland, 1985, p. 106)
Don’t focus on Chinese room example only, focus on the whole argument in Searle’s paper. “A computer whose only input and output was verbal would always be blind to the meaning of what was written“ (Dennett 1969, p . 182). Searle’s argument
1. Carrying out a computer program does not suffice for understanding Chinese. • Searle doesn’t understand the Chinese stories. 2. The program is en rely irrelevant to explaining understanding. • Carrying out the program doesn’t get Searle any closer to understanding Chinese.
3. So func onalism is false: • Programs for manipula ng symbols can’t explain your understanding of ‘restaurant’ • And so func onalism can’t explain your beliefs and desires about restaurants.
40 1. The systems reply • Searle is just one component of the whole computer system including: • Book, • Ini al Chinese symbols, • Paper, pencil, scratch paper, • Room, etc. • He may not understand Chinese, but the system as a whole does!
Response: Searle could memorize the instruc ons, do the calcula ons in his head, leave the room. He s ll wouldn’t understand Chinese!
41 Subsystems?
There are two subsystems in Searle: • The ‘English’ computer program • The ‘Chinese’ computer program Both subsystems fully understand their languages. But the two programs aren’t hooked up. So when he’s speaking English, Searle falsely claims he doesn’t understand Chinese, and vice versa.
Response: There’s no reason to think the Chinese subsystem understands anything at all!
42 2. The robot reply
The problem with the Chinese room is it doesn’t have the normal sensory inputs & behavioral outputs required by func onalism. If you hook the Chinese room up to a robot in the right way, it will understand Chinese.
Response: The sensory inputs & behavioral outputs will just be more incomprensible symbols to the person in the room. So he s ll won’t understand!
43 3. The brain simulator reply
What about the computer program instan ated at the level of our neural architecture, with massively parallel processing? Surely that program will understand Chinese.
Responses: 1. This func onalist will give up some mul ple realizability and independence from biology. (cf. Block) 2. Searle could run this program instan ated in the room with water-pipes, and he s ll wouldn’t understand Chinese!
44 4. The combina on reply Combine the first three strategies: 1. Create an exact computer simula on of a chinese speaker’s brain, down to the last synapse. 2. Hook it up to a robot. 3. Pay a en on to the states of the system as a whole, rather than any subsystem. It would be irra onal to deny that this robot understands Chinese!
Response: That’s because it would behave like a Chinese speaker. But if we knew it was just manipula ng symbols, we would deny that it understands anything!
45 What’s Searle’s alterna ve? ‘It is not because I am the instan a on of a computer program that I am able to understand English and have other forms of inten onality…, but as far as we know it is because I am a certain sort of organism with a certain biological (i.e. chemical and physical) structure, and this structure, under certain condi ons, is causally capable of producing percep on, ac on, understanding, learning and other inten onal phenomena. And the point of the present argument is that only something that had those causal powers could have that inten onality. Perhaps other physical and chemical processes could produce exactly these effects; perhaps, for example, Mar ans also have inten onality but their brains are made of different stuff. That is an empirical ques on, rather like the ques on of whether photosynthesis can be done by something with a chemistry different from that of 46 chlorophyll.’ 4. The Self If you teletransport to another planet, we might wonder whether the resulting individual is you---whether you've really survived. Parfit argues that identity is not what matters when we consider our futures in such cases. How does he reach this conclusion by considering the problem of fission? Is this a good argument? Is there more reason to think that identity does matter to survival? (Here you might focus more on Williams or Lewis, rather than discussing them both in detail.)
Required reading: Derek Parfit, 'Personal Identity' Bernard Williams, 'The Self and the Future' David Lewis, 'Survival and Identity' What makes someone the same person over me? Locke: Memory; Reid: Persons are con nuing en es; Butler: Memory presupposes personal iden ty, because there needs to be a consciousness to do the remembering; Parfit: Not iden ty, survival; Williams: Not psychological survival, bodily survival; Lewis: Connected temporal-person- stages. Teleportation
Imagine a teleport machine that works as follows. It scans and records everything about your body, down to the atomic level. That information is then sent to the receiving teleport machine, which reconstructs your body exactly from a stock pile of raw material. The scanning process destroys all the original atoms of your body. Question: Is this really a way to travel? Would you use it? Is the person who arrives at the destination you? Teleportation Teleportation Imagine the machine breaks down. An exact duplicate of you is created at the destination, but the original you is not destroyed. Or what if two copies of you were created at the other end?
Again, the person / people at the other end are psychologically continuous with you, But are they really you? Most people answer no – this kind of machine is not a way to travel. It just creates a duplicate of you (like an identical twin).
Perhaps it is bodily continuity that really matters then, rather than psychological continuity. (Williams)
Parfit’s argument
(1) Identity is a one-one relation that does not admit of degrees. (2) Psychological continuity need not be one- one and can come in degrees. (Fission and fusion cases) (3) What matters in survival is psychological continuity (whether your mental life continues on) Therefore: (C) What matters in survival is not identity.
Lewis wants to accept all three premises, but reject the conclusion. Temporal stages
Lewis makes use of the idea that a person is a unified whole consisting of temporal stages or temporal parts.
Think of a person as a four-dimensional object which is stretched out in time. At any particular time, only the temporal parts are present, never the whole person.
This conception of identity through time should be distinguished from an endurantist conception, according to which the whole person is present at all the times that it exists. Tensed Iden ty
“You may feel certain that you count persons by identity and not tensed identity. But how can you be sure? Normal cases provide no evidence…. The problem cases provide no very solid evidence either. They are problem cases just because we cannot consistently say quite all the things we feel inclined to, We must strike the best compromise among our conflicting opinions. Something must give way: and why not the opinion that of course we count by identity, if that is what can be sacrificed with the least total damage?” Lewis, ‘Survival and Identity’, p. 227