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1 Copyright © 2011 Pearson Education, Inc. All rights reserved.

2 David Hume  British Empiricism – a belief system that all knowledge is based on ideas developed from sense data or sensory experience  David Hume( ) (Treatise on Human Understanding, 1739) 3 Minute Philosophy: David Hume

3 Empiricist Epistemology  Epistemology  The study of knowledge (how and what we can know)  Knowledge = true beliefs, thoughts, propositions  Truth = a belief or proposition is said to be true if it corresponds to reality  Ex: The proposition “this sentence has 5 words” is true if it actually has 5 words.  Empiricist epistemology:  knowledge consists of ideas that are true (correspond to reality)  Ideas are objects of cognition  All ideas/objects of cognition are derived from either sensation or reflection  In order for an idea to be true, it must ultimately have as its source sensory experience with sense date and it must be verified/checked by experience  All knowledge begins with experience and is limited to experience

4 Positivism  Also known as logical positivism and/or scientific positivism  Positivism: a radical 20 th century empiricist position that maintains that propositions are meaningful if and only if they are:  Analytically true, i.e., logically true, true by definition  A triangle is a three sided object with internal angles that add up to 180 degrees  Synthetically true, i.e., true empirically, factually verifiable  This sentence has 5 words. The chalk is white  Any claims that are not true analytically or factually are meaningless  Hume’s Fork: propositions are true if they are about  Relations of ideas: “analytic a priori” claims  Matters of fact: “synthetic a posteriori” claims

5 Representational Realism Copyright © 2011 Pearson Education, Inc. All rights reserved.  Epistemological position that all knowledge is based on ideas developed from sense data from sensory experience of the world  1 st 2 nd 3 rd 4 th The worldBody Mind Knowledge Presents itselfSensation Cognition ExpressionImpression Idea True claim/belief Objective TRUTH = Accurate representation of objects in reality

6 PRIMARY AND SECONDARY QUALITIES  Primary qualities “resemble” (or “reside in”) an object even when we are not perceiving the object  Solidity  Extension  Figure (shape)  Motion or rest  Number  Objective knowledge  Secondary qualities do not “resemble” (or “reside in”) an object, but are “powers” of objects to produce sensations in our minds  Colors  Sounds  Tastes  Odors  Subjective knowledge

7 Copyright © 2011 Pearson Education, Inc. All rights reserved. The Fate of Empiricism  With the success of Newtonian physics and Locke’s account of an empiricist metaphysics and epistemology  Empiricism seemed to clearly have the upper hand against rationalism  Hume comes along and shows that there is something deeply troubling about empiricism  It leads to a radical kind of skepticism

8 Copyright © 2011 Pearson Education, Inc. All rights reserved. “HUME’S FORK”: RELATIONS OF IDEAS AND MATTERS OF FACT  Relations of Ideas  Mathematical statements, such as those found in geometry, algebra, and arithmetic  Tautologies, or logical truths, such as “A dog is a dog”  Known by reason  To deny them is to contradict oneself; therefore, they give us absolute certainty  But they have no empirical content  Matters of Fact  Involve sense experience  It is possible to logically contradict a matter of fact  Hume believes that if a claim of empirical knowledge cannot be reduced to a relation of ideas or a matter of fact, it should be discarded as knowledge. He challenges:  Any necessary connection between cause and effect  The notion of material substance  The notion of mental substance (“soul”)  Inductive reasoning

9 Copyright © 2011 Pearson Education, Inc. All rights reserved. Relations of Ideas vs Matters of Fact  Human knowledge falls into two kinds for Hume  Relations of Ideas– all a priori knowledge  Matters of Fact– all empirical knowledge  To decide which is which you apply the following rule  If the negation of the proposition in question is a contradiction then it is a Relation of Ideas  If not, a Matter of Fact

10 Copyright © 2011 Pearson Education, Inc. All rights reserved. RoI & MoF  R elations o f I deas  All bachelors are unmarried  All dogs have doggie anatomies and physiologies  All apples have colored skin with flesh surrounding a core of seeds  All triangles have three sides A 2 +B 2 =C 2  For any sentence S, either S is true or S is false  S can’t be true and also not true at the same time  M atters o f F act  78% of bachelors are messy  Whether a dog has short legs and a big bark  Whether an apple is red or green  Whether a triangle is 3x3x3 or 4x4x4  Subway fare is $2.00  The truth or falsity of S is dependent upon the circumstances

11 Copyright © 2011 Pearson Education, Inc. All rights reserved. RoI  Relations of ideas consists of two parts  Ideas  And the relations between them  E.g. my ideas BACHELOR and UNMARRIED MALE are related in such a way as to make it impossible for there to be a married bachelor  This is true for all relations of ideas  Their truth is independent of experience in the sense that one does not need to go and check to see if they are true  Mathematics and logic are purely formal systems of inter-related definitions  Numbers do not need to exist to make it true that 2+2-4

12 Copyright © 2011 Pearson Education, Inc. All rights reserved. MoF  Matters of Fact on the other hand have their truth determined by the way that the world happens to be  Hume argues that the idea of cause and effect is a MoF because it fails to meet the two criteria of something that is a priori  To deny it is not a contradiction  We cannot, without experience, predict what the effect of any given cause will be

13 Analytic apriori vs. Synthetic aposteriori  Analytic apriori  Relations of Ideas  Analytic apriori  Deduction  True by definition (universally and necessarily)  Absolutely certain  Snythetic aposteriori  Matters of Fact  Synthetic aposteriori  Induction  Truth is contingent  Probability

14 Summary of the Argument so Far  All human knowledge is either learned from experience (matters of fact) or from reason (relation of ideas)  MoF are composed of ideas copied from impressions and are true or false depending on the kind of experience we have  ‘dogs can fly’ vs. ‘dogs don’t like cats’  RoI are true or false depending on the relations that hold between the ideas  ‘triangles are four-sided objects’ vs. ‘triangles have three sides’  We can tell the difference between these by seeing what happens when we negate the sentence in question  If it is a contradiction it is a RoI, if not a MoF

15 The Argument III  All of our ideas must come from one of these two sources  One of the most important ideas we have is the idea of causation  The idea of a necessary connection between events  Same cause=same effect EVERY TIME  All of science is based on this idea  All of our common sense knowledge about the world based on this idea

16 The Problem of Causality  So, where does the concept of causality come from?  Is it an innate idea? No  Is it an idea that is necessitated by and/or related to other ideas? That is, is it derived from some other idea, such as thing, self, substance, God, etc.? No  Is it an idea that can be traced back to an experience of a primary quality in the world? NO

17 Causality ≠ a relation of ideas  Causality is not an RoI  To deny any causal relation is not a contradiction  It is always possible to imagine something else happening  But we can’t imagine a square circle  We have to go and check  We can’t tell what causes what without experience

18 Causality ≠ MoF  So, it must be a MoF  That means that the idea of necessary connection must be traceable back to an impression  Otherwise it is a meaningless idea  But when we look at any example of A causing B all we see are separate events  We see A happen (the pool stick hits the ball)  Then we see B happen (the second ball moves)

19 Causality ≠ MoF (#2)  We do not see anything that connects the two events  There is nothing that we can point to and say that it is the thing that makes the second event the necessary consequence of the first event  So, Hume concludes, we have no rational reason (i.e. based on our experience or reason) to believe that the laws of physics are necessary and universal

20 Causal claims are inductively fallacious  All inductive knowledge is based on the fallacy of assuming that the future will resemble the past  But just because something has happened for a long time is no guarantee that it will always happen  So, the sun may have risen everyday so far, but who can say with certainty that it will rise tomorrow?  Just like problem of black swans

21 Solution: Causality is the product of habit  So where does the idea come from?  It comes from ‘a habit of expectation’  We see A happen  We see B happen right after  We see A happen  We see B happen right after  This is repeated  Soon when we see A happen we come to expect that B will happen right after

22 Causality = a projection of the Mind  It is the subjective feeling of expectation that we mistakenly ‘project’ out onto the events that we observe  We cannot know if there is anything more to the word than this  This is an epistemological claim: we can’t know if there is a necessary connection between events  NOT a metaphysical claim: There is no necessary connection between events

23 Copyright © 2011 Pearson Education, Inc. All rights reserved. Pavlov & Classical Conditioning  We have been trained by nature to expect certain events upon seeing certain other events  Just like Pavlov’s dog  You ring the bell and bring some food  The dog salivates  Repeat  Soon the dog salivates when hearing the bell whether or not food comes  The dog has come to expect ‘bell then food’

24 Copyright © 2011 Pearson Education, Inc. All rights reserved. Classical Conditioning II  Now if the dog were to reason to itself as follows,  Every time the bell has rang food has appeared  This has happened everyday of my existence, every since I was a puppy  I can infer from this that the next time the bell rings, food will appear  We could easily see that the dog has made a mistake

25 Copyright © 2011 Pearson Education, Inc. All rights reserved. Classical Conditioning III  There is no necessary connection between bell ringing and food appearing in nature  How can we tell that this is not the way nature is in reality?  Nature is regular (so was the bell ringing/food bringing relationship)  Things so far have happened regularly and predictably  But we have no reason to believe that it must continue

26 Copyright © 2011 Pearson Education, Inc. All rights reserved. READING CRITICALLY: ANALYZING HUME’S CASE FOR SKEPTICISM  Is Hume correct to call the appeal to God’s existence to support the existence of an external world “philosophical hypocrisy”? Why or why not?  Summarize Hume’s arguments against certain knowledge of the principle of cause and effect. Do you agree with his reasoning? Why or why not? Construct an alternative argument to convince Hume that the principle of cause and effect is valid and give examples.  Would your agreeing with Hume’s critique of knowledge claims about cause and effect and induction change the way you live your life? Why or why not?  Hume splits his practical life from his theoretical philosophical commitments. Do you agree that such a split is possible? Should our choices in life reflect our epistemological convictions? Describe an example to support your point of view.  Hume believes that all metaphysical beliefs (that is, any belief not based on direct sense experience) should be “committed to the flames” because they cannot be empirically justified. This would include all beliefs regarding God, human freedom, universal moral laws, and so on. Do you agree with Hume? If not, how would you rebut his arguments?

27 Copyright © 2011 Pearson Education, Inc. All rights reserved. KANT’S “COPERNICAN REVOLUTION” “Hitherto it has been assumed that all our knowledge must conform to objects. But all attempts to extend our knowledge of objects by establishing something in regard to them by means of concepts have, on this assumption, ended in failure. We must, therefore, make trial whether we may have more success if we suppose that objects must conform to our knowledge.” –Critique of Pure Reason

28 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s Dogmatic Slumber  Kant is disturbed from thinking that everything in science is fine by Hume’s argument  Empiricism cannot deliver necessary truths  ‘experience can teach us that something is the case but it cannot teach us that it must be the case’  Yet science claims to discover necessary truths about nature  Even worse, Hume claimed to have shown that Human Beings are essentially irrational

29 Copyright © 2011 Pearson Education, Inc. All rights reserved. Transcendental Idealism  Kant agrees with Hume that we cannot learn that the causal relation is necessary and universal from experience  But Hume has not shown that we can’t have a priori knowledge  For Hume something was a priori if we could not deny it without contradiction  For Kant something is a priori if is knowable completely independently of experience

30 Copyright © 2011 Pearson Education, Inc. All rights reserved. An Analogy  Suppose that I told you that there were 25 people in a room on the second floor of some building  What could you know about that room?  Quite a bit actually  Its size, what it was made out of, etc.  Kant’s strategy is similar  He wants to know what we can know given that our experience is the way that it is

31 Copyright © 2011 Pearson Education, Inc. All rights reserved. The Structure of Experience  How could our experience be the way that it is?  How is it?  Objects are located in space and time  Can you imagine an object which was not at any place?  No  This is something that we can know a priori  It is not dependent on experience

32 Copyright © 2011 Pearson Education, Inc. All rights reserved. Conditions of all Possible Experience  It is the pre-condition for any experience at all  Just like space in the room is a precondition of having objects in the room  So too space is a necessary condition of any possible experience  Thus we can know with absolute certainty that whatever experiences we do have  They will all take place at some time and at some particular place

33 Copyright © 2011 Pearson Education, Inc. All rights reserved. The A Priori  So Kant concludes that there is pure A priori knowledge  ‘pure’ because it does not depend on experience  But is rather the pre-conditions for any possible experience  It is necessary  It is not possible to have experience without space  And universal  All experiences will be in space

34 Copyright © 2011 Pearson Education, Inc. All rights reserved. Analytic vs. Synthetic  An analytic truth is one that is true by virtue of the meaning of the words themselves  All bachelors are unmarried males  They do not add to our knowledge  Synthetic truths are true in virtue of the kind of experience we have  All bachelors are messy  They do add to our knowledge

35 Copyright © 2011 Pearson Education, Inc. All rights reserved. Hume’s Mistake  Hume’s criterion for being a priori  P is a priori if the denial of p is a contradiction  Let him divide all of our knowledge into that which was necessary (RoI) and that which was contingent (MoF)  Kant argues that we really have four categories  Analytic & A priori – truths which are true by definition and also necessary and universal  All analytic truths are a priori

36 Copyright © 2011 Pearson Education, Inc. All rights reserved. Hume’s Mistake II  Analytic & A posteriori – truths which are true by definition but also discovered by experience  Kant denied that there were any such truths  Synthetic A posteriori– Adds to our knowledge and learned from experience  Synthetic A priori– Adds to our knowledge and also necessary and universal  Hume denied that there were any such truths  That was his mistake

37 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s 4 Distinctions A Priori A Posteriori Analytic Synthetic All Bachelors are unmarried males All triangles have three sides Dogs bark Apples taste good 7+5=12 ?????? ? Cause & effect !!!!!!

38 Copyright © 2011 Pearson Education, Inc. All rights reserved. Synthetic A Priori Knowledge  So Kant’s answer to Hume is his theory of synthetic a priori knowledge  Take ‘fire causes pain’  It is synthetic, it adds to our experience  But it is also a priori, that is, necessary and universal  It is a priori in the sense that we can tell by looking at the structure of our experience that it must be a certain way  This Kant calls phenomena

39 Copyright © 2011 Pearson Education, Inc. All rights reserved. Phenomena vs. Noumena  The phenomenal world is the world as it appears to us.  It is the world that we see touch taste etc.  The noumenal world is the way that the world is in-itself  The world as it is when no one is looking at it  All we can know is the way our experience of the world will be  We can’t know the noumenal world

40 Copyright © 2011 Pearson Education, Inc. All rights reserved. Phenomena v. Noumena II Noumena Understandin g Sensibility Hi Wasup ?

41 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s Philosophy of Mind  The mind has two components  Sensibility  Understanding  Sensibility takes in ‘raw’ unorganized noumena and organizes it into phenomena (our experience)  Each has their categories that they use in order to construct our experience  The sensibility has Space and Time

42 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s Philosophy of Mind II  The understanding has 12 categories  Unity, plurality, totality, reality, negation, limitation, substance/property, cause & effect, community, possibility/impossibility, existence/non-existence, and necessary/contingent  With these categories, and the two from the sensibility, our mind constructs our experience  We can know with absolute certainty that our experience will conform to the categories

43 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s Philosophy of Mind IV  That is the only way that experience like ours is possible  The same cause must bring about the same effect or else our experience would be like a dream  Now here, now there…  Yet this comes at a heavy cost  Science studies our experience of the world  It does not, cannot, study the noumenal world  How can I every talk to you?

44 Copyright © 2011 Pearson Education, Inc. All rights reserved. Phenomena v. Noumena III Hi Wasup ? Hi Wasup ? Me You

45 Copyright © 2011 Pearson Education, Inc. All rights reserved. Kant’s Philosophy of Mind V  Kant called this a Copernican Revolution in philosophy  Instead of the mind passively acting like a recorder of an outside reality  Kant sees the human mind as actively constructing reality  This is his mix of Rationalism and Empiricism  Empiricism– science is synthetic knowledge  Rationalism– but based on a priori categories

46 Copyright © 2011 Pearson Education, Inc. All rights reserved. KANT ON THE SYNTETIC A PRIORI AND THE PHENOMENAL AND NOUMENAL WORLDS THE SYNTHETIC A PRIORI  Necessary and universally true  a priori—can be discovered independently of experience  Synthetic in the sense that it provides us with genuine information regarding our experience in the world THE PHENOMENAL AND NOUMENAL WORLDS  phenomenal reality is the world as we constitute it and experience it  noumenal reality is the world beyond our perceptions, reality “in-itself”

47 Copyright © 2011 Pearson Education, Inc. All rights reserved. APPLYING KANT’S THEORY: THE ASSASSINATION OF MALCOLM X

48 Copyright © 2011 Pearson Education, Inc. All rights reserved. ALLISON JAGGAR: EMOTIONS SHAPE OUR UNDERSTANDING  Jaggar believes that the “new science” of Newton and Galileo spawned a wide split between reason and emotion, so that “dispassionate” reason was considered the only source of knowledge  She argues that “dispassionate investigation” is a myth, and that emotions should be incorporated into our epistemological framework, including the framework of scientific knowledge


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