Lecture 6

1.1. Essay #1 and writing a philosophy paperEssay #1 and writing a philosophy paper2.2. Brain teasersBrain teasers3.3. The Problem of InductionThe Problem of Induction4.4. Hume’s conclusionHume’s conclusion5.5. How, if at all, do his arguments need updating (or How, if at all, do his arguments need updating (or

have we solved the problem of induction?)have we solved the problem of induction?)

Essays

Essay #1 is now due Essay #1 is now due May 6 rMay 6 rather than April 28, at ather than April 28, at the beginning of section. the beginning of section.

For the topic and directions, use the link “Paper For the topic and directions, use the link “Paper Topics” on the main webpage.Topics” on the main webpage.

In sections, you will engage in peer review of drafts In sections, you will engage in peer review of drafts of your essays (date to be announced). of your essays (date to be announced).

If you want your TA to read a draft and provide If you want your TA to read a draft and provide feedback (you are seeking W credit), you must get it feedback (you are seeking W credit), you must get it to him by … to him by …

Due date/time is firm. You will lose credit if your Due date/time is firm. You will lose credit if your paper is late.paper is late.

EssaysWriting a philosophy paperWriting a philosophy paper

Unless otherwise noted, a philosophy paper is not a research Unless otherwise noted, a philosophy paper is not a research paper. Your sources should only include course readings, paper. Your sources should only include course readings, discussions, lectures, films, etc. Strong words of advice: do discussions, lectures, films, etc. Strong words of advice: do not use the internet!not use the internet!

Common types of philosophy papers:Common types of philosophy papers:Explication (of an issue and argument -- our first essay)Explication (of an issue and argument -- our first essay)Assertion papers (“I agree that x for reasons a,b,c”)Assertion papers (“I agree that x for reasons a,b,c”)Refutations (“I disagree for reasons a,b,c”)Refutations (“I disagree for reasons a,b,c”)Position papers (“What objectivity is [or is not]”Position papers (“What objectivity is [or is not]”DialoguesDialoguesCase studies (to draw a philosophical conclusion)Case studies (to draw a philosophical conclusion)

EssaysWriting in philosophy serves three purposes: clarification, Writing in philosophy serves three purposes: clarification,

exploration, and communication.exploration, and communication.The simple act of writing something down makes thinking The simple act of writing something down makes thinking

easier (particularly about topics or issues that are easier (particularly about topics or issues that are abstract and/or complex).abstract and/or complex).

Writing also provides a concrete way to re-think your ideas Writing also provides a concrete way to re-think your ideas or assumptions: you may find your original assumption or assumptions: you may find your original assumption unclear, not fully warranted, wrong, and so forth.unclear, not fully warranted, wrong, and so forth.

Writing is the chief mode of communicating in philosophy: if Writing is the chief mode of communicating in philosophy: if you want to demonstrate your understanding to a you want to demonstrate your understanding to a professor, if you want to relate an abstract idea to your professor, if you want to relate an abstract idea to your own experience, if you want to persuade someone that own experience, if you want to persuade someone that your position is the correct one…your position is the correct one…

EssaysMany of us enter university without having learned the skills Many of us enter university without having learned the skills

needed to write a good philosophy paper or essay. needed to write a good philosophy paper or essay. Learning these skills is incremental (moving, for example, Learning these skills is incremental (moving, for example,

from writing a paper that seeks to explicate an issue and from writing a paper that seeks to explicate an issue and relevant arguments, to writing a position paper).relevant arguments, to writing a position paper).

Things to keep in mind as you begin work on your first essay:Things to keep in mind as you begin work on your first essay:Writing is a process, not an end product or a last-minute Writing is a process, not an end product or a last-minute

grind.grind.““Pre-writing”: be sure you understand the assignment. Pre-writing”: be sure you understand the assignment. Ask for clarification if you are not sure. Ask for clarification if you are not sure. Some find “brainstorming” and “free writing” helpful.Some find “brainstorming” and “free writing” helpful.

EssaysWriting is a process, not an end product or a last-Writing is a process, not an end product or a last-

minute grind.minute grind.““Pre-writing”Pre-writing”Scheduling: have a plan for when a first draft will Scheduling: have a plan for when a first draft will be complete (at least before peer reviews in be complete (at least before peer reviews in section), when you will return to it to take a section), when you will return to it to take a closer look, and when you will spend time closer look, and when you will spend time “polishing” the final version.“polishing” the final version.Revising a paper is one of the few chances we Revising a paper is one of the few chances we have in life for “a second chance”.have in life for “a second chance”.

EssaysRevising in light of another’s review or your own:Revising in light of another’s review or your own:IntroductionIntroduction

Does it clearly define the topic and forecast the rest of the Does it clearly define the topic and forecast the rest of the essay? (yes or needs attention -- with recommendations)essay? (yes or needs attention -- with recommendations)

Body of essay:Body of essay:Transition from introductionTransition from introductionUse of example(s): well executed, appropriate example?Use of example(s): well executed, appropriate example?Completeness of information (accurate and complete Completeness of information (accurate and complete explication of an argument)explication of an argument)

ConclusionConclusionTransition from body of essayTransition from body of essaySummationSummation

CLARITY, CLARITY, CLARITYCLARITY, CLARITY, CLARITY

Part IIPart II

Logic Puzzles Logic Puzzles

(Mental gymnastics before we (Mental gymnastics before we approach Hume!)approach Hume!)

Part IIIPart III

Hume’s Problem of InductionHume’s Problem of Induction

Inductive reasoningInductive reasoning

Science and we assume causation (cause and Science and we assume causation (cause and effect relationships)effect relationships)

For empiricists, all the evidence there is for For empiricists, all the evidence there is for empirical knowledge concerning “matters of empirical knowledge concerning “matters of fact,” including scientific knowledge is sensory fact,” including scientific knowledge is sensory experienceexperience

For some empiricists – including Hume – we For some empiricists – including Hume – we move from individual experiences/singular move from individual experiences/singular statements to generalizations/universal statements to generalizations/universal statements using induction (and we certainly statements using induction (and we certainly do this a lot) do this a lot) presumingpresuming causation. causation.

Empirical generalizationsEmpirical generalizations1.1. Millions of ravens have been observed and all are black.Millions of ravens have been observed and all are black.

2.2. A non-black raven has never been observed.A non-black raven has never been observed.

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3.3. All ravens are blackAll ravens are black Are, like other forms of inductive arguments, Are, like other forms of inductive arguments, ampliative ampliative – –

the conclusion goes beyond the premisesthe conclusion goes beyond the premises Reasoning moves from the past and present to the futureReasoning moves from the past and present to the future From what has been experienced to what has notFrom what has been experienced to what has not From a finite (however large) set of experiences to an From a finite (however large) set of experiences to an

infinite number of occurrencesinfinite number of occurrences

Hume’s questionHume’s question What What justifiesjustifies our use of induction? our use of induction?

What warrants our using it?What warrants our using it? He believes there are two places to look for such He believes there are two places to look for such

justification:justification: Our experiences (which concern “matters of fact”)Our experiences (which concern “matters of fact”) Reason (which he calls “relations of ideas” and Reason (which he calls “relations of ideas” and

“demonstrative knowledge”). What he means is “demonstrative knowledge”). What he means is deductively valid reasoning deductively valid reasoning as we find in mathematics, as we find in mathematics, etc.etc...

And proposes we explore each to see if we can And proposes we explore each to see if we can discover what justifies inductive reasoning…discover what justifies inductive reasoning…

Hume’s questionHume’s questionCan Can reasonreason (demonstrative knowledge) provide the (demonstrative knowledge) provide the

justification?justification?No.No.There is no There is no necessary connectionnecessary connection (as there is in ‘2 + 2= 4) (as there is in ‘2 + 2= 4)

betweenbetween““I’ve always (and so has everyone else) experienced that I’ve always (and so has everyone else) experienced that X causes Y”X causes Y”andand““The next X I encounter will cause Y”The next X I encounter will cause Y”

It is possible, reason tells us, that despite all previous It is possible, reason tells us, that despite all previous experiences, in our next encounter x will not cause y!experiences, in our next encounter x will not cause y!

Hume’s questionHume’s questionCan Can reasonreason (demonstrative knowledge) provide the (demonstrative knowledge) provide the

justification?justification?No.No.The argument is inductive, not deductively valid.The argument is inductive, not deductively valid.It is ampliative: moving from the past and present to the It is ampliative: moving from the past and present to the

future, and moving from a finite (however large) set of future, and moving from a finite (however large) set of experiences to the future and an infinite set of experiences to the future and an infinite set of occurrences. occurrences.

So reason (as Hume understands it) cannot justify inductive So reason (as Hume understands it) cannot justify inductive reasoning.reasoning.

Hume’s questionHume’s questionCan Can experience experience justify our use of induction?justify our use of induction?Say, we argue:Say, we argue:

Induction has worked in the past and present to allow us Induction has worked in the past and present to allow us to predict events/phenomena.to predict events/phenomena.----------------------------------------------------------------------------------------------------------------------------------------------------So, induction will work in the future to allow us to So, induction will work in the future to allow us to predict events/phenomena.predict events/phenomena.

If this reasoning doesn’t justify induction, why doesn’t it?If this reasoning doesn’t justify induction, why doesn’t it?It’s It’s circularcircular: it’s using inductive reasoning to justify inductive : it’s using inductive reasoning to justify inductive

reasoning!reasoning!

Hume’s questionHume’s question

Can Can experience experience justify our use of induction?justify our use of induction?Maybe if we add a premise:Maybe if we add a premise:Say, we argue:Say, we argue:

Induction has worked in the past and present to allow us Induction has worked in the past and present to allow us to predict events/phenomena.to predict events/phenomena.Nature is uniformNature is uniform----------------------------------------------------------------------------------------------------------------------------------------------------So, induction will work in the future to allow us to So, induction will work in the future to allow us to predict events/phenomena.predict events/phenomena.

This is a This is a deductively valid argumentdeductively valid argument, so why can’t it solve the , so why can’t it solve the problem of induction?problem of induction?

Hume’s conclusionsHume’s conclusionsInductive reasoning is just a Inductive reasoning is just a habithabit of ours and cannot be of ours and cannot be

justified on either empirical grounds or through reason.justified on either empirical grounds or through reason.But it seems to be an But it seems to be an unavoidableunavoidable habit, common to young habit, common to young

children as well as adults.children as well as adults.So the skeptical conclusion – that it cannot be justified – is So the skeptical conclusion – that it cannot be justified – is

limited in its actual consequences.limited in its actual consequences.We all (including Hume!) will continue to engage in it and We all (including Hume!) will continue to engage in it and

should go on living as if it is okay… but realizing, at a should go on living as if it is okay… but realizing, at a philosophical level, that it isn’t justifiable.philosophical level, that it isn’t justifiable.

So, I (says Hume) will go on tonight to have a glass of my So, I (says Hume) will go on tonight to have a glass of my favorite wine, listen to my favorite music, assume the favorite wine, listen to my favorite music, assume the sun will rise tomorrow, and so forth…sun will rise tomorrow, and so forth…

Salmon’s physics studentSalmon’s physics studentwho is also studying Hume!who is also studying Hume!

First hypothesis: Hume’s problem is not any First hypothesis: Hume’s problem is not any longer a problem as those “secret powers” he longer a problem as those “secret powers” he refers to (for example, why bread nourishes refers to (for example, why bread nourishes us) are now us) are now knownknown. .

Given that we now know many Given that we now know many causescauses he he didn’t know, we also know why inductive didn’t know, we also know why inductive reasoning from past and present to future, reasoning from past and present to future, from a finite number of cases to an infinite from a finite number of cases to an infinite number, number, isis justifiedjustified..

Salmon’s physics studentSalmon’s physics studentwho is also studying Hume!who is also studying Hume!

Second hypothesis: Hume’s problem is not any Second hypothesis: Hume’s problem is not any longer a problem because since his time, we have longer a problem because since his time, we have discovered many laws of nature: conservation of discovered many laws of nature: conservation of energy, conservation of momentum, etc. which energy, conservation of momentum, etc. which allow us to predict (correctly) the outcome of any allow us to predict (correctly) the outcome of any and all relevant experiments and occurrences.and all relevant experiments and occurrences.

His professors in physics and research assistants His professors in physics and research assistants have shown him many experiments that have shown him many experiments that demonstrate the laws are true and without demonstrate the laws are true and without exceptions!exceptions!

Salmon’s physics studentSalmon’s physics student

And given increased knowledge in a variety of And given increased knowledge in a variety of sciences, we now know that the argument:sciences, we now know that the argument:

1.1. On every day in recorded time, the sun rose (and On every day in recorded time, the sun rose (and on days before recorded time, if it had not, on days before recorded time, if it had not, organisms would have died and we could verify organisms would have died and we could verify that).that).

2.2. Physics and astronomy explain why the sun always Physics and astronomy explain why the sun always rises.rises.

----------------------------------------------------------------------------------------------------------------------------------So, the sun always rises (or will rise tomorrow)So, the sun always rises (or will rise tomorrow)is deductively valid.is deductively valid.

The physics student’s professorsThe physics student’s professors

His philosophy TA: did your physics professor say His philosophy TA: did your physics professor say that the laws of conservation of energy and that the laws of conservation of energy and momentum are, by their nature, inviolable, or momentum are, by their nature, inviolable, or that there are that there are no known exceptionsno known exceptions? The latter!? The latter!

His physics professors to whom he asks “Is it His physics professors to whom he asks “Is it possible that any or all of these laws will possible that any or all of these laws will stop stop holding tomorrow or on some future date?holding tomorrow or on some future date?””

Their answer: Yes. There is no guarantee, based on Their answer: Yes. There is no guarantee, based on either all of our experiences or our theories, either all of our experiences or our theories, that nature will continue to behave the way it that nature will continue to behave the way it has in the future. We believe it based on faith.has in the future. We believe it based on faith.

What to think of the problem of induction?What to think of the problem of induction?

Many have worked to develop probability theories Many have worked to develop probability theories so as to be able to replace “provable” with so as to be able to replace “provable” with “probable to some degree or other” as useful in “probable to some degree or other” as useful in evaluating empirical/scientific theories.evaluating empirical/scientific theories.

Strictly speaking, the probability of a generalization Strictly speaking, the probability of a generalization or universal statement (of which hypotheses or universal statement (of which hypotheses and theories are kinds thereof) based on a finite and theories are kinds thereof) based on a finite number of occurrences/events – however large number of occurrences/events – however large – is zero. But if we don’t assume anyone can – is zero. But if we don’t assume anyone can have a goddess’s eye view, we can settle for a have a goddess’s eye view, we can settle for a less exacting understanding of probability.less exacting understanding of probability.

What to think of the problem of induction?What to think of the problem of induction?

Can evolutionary theory and/or cognitive science Can evolutionary theory and/or cognitive science help with the problem?help with the problem?

Suppose, as they propose and seems reasonable, Suppose, as they propose and seems reasonable, that for our ancestors, classifying plants, that for our ancestors, classifying plants, animals, other humans, and physical events animals, other humans, and physical events brought helpful order to their world view and brought helpful order to their world view and enabled them to make predictions (“Don’t go enabled them to make predictions (“Don’t go near tigers when they’re hungry or you, like our near tigers when they’re hungry or you, like our friend Joe, will be their lunch”) that enhanced friend Joe, will be their lunch”) that enhanced their survival.their survival.

What to think of the problem of induction?What to think of the problem of induction?

Can evolutionary theory and/or cognitive science Can evolutionary theory and/or cognitive science help with the problem?help with the problem?

Well it would Well it would explainexplain the habit Hume described, but the habit Hume described, but would it would it justifyjustify the use of induction? the use of induction?

No, as it remains the case that there is nothing we No, as it remains the case that there is nothing we can point to in terms of our experiences or can point to in terms of our experiences or theories that guarantees that nature will remain theories that guarantees that nature will remain uniformuniform

Even in the next fifteen minutes.Even in the next fifteen minutes.So we might need to settle for explanation rather So we might need to settle for explanation rather

than justification of inductive reasoning.than justification of inductive reasoning.