Lecture 6 1. Essay #1 and writing a philosophy paper 2. Brain teasers 3. The Problem of Induction 4. Hume’s conclusion 5. How, if at all, do his arguments need updating (or have we solved the problem of induction?)

Essays  Essay #1 is now due May 6 rather than April 28, at the beginning of section.  For the topic and directions, use the link “Paper Topics” on the main webpage.  In sections, you will engage in peer review of drafts of your essays (date to be announced).  If you want your TA to read a draft and provide feedback (you are seeking W credit), you must get it to him by …  Due date/time is firm. You will lose credit if your paper is late.

Essays Writing a philosophy paper Unless otherwise noted, a philosophy paper is not a research paper. Your sources should only include course readings, discussions, lectures, films, etc. Strong words of advice: do not use the internet! Common types of philosophy papers: Explication (of an issue and argument -- our first essay) Assertion papers (“I agree that x for reasons a,b,c”) Refutations (“I disagree for reasons a,b,c”) Position papers (“What objectivity is [or is not]” Dialogues Case studies (to draw a philosophical conclusion)

Essays Writing in philosophy serves three purposes: clarification, exploration, and communication. The simple act of writing something down makes thinking easier (particularly about topics or issues that are abstract and/or complex). Writing also provides a concrete way to re-think your ideas or assumptions: you may find your original assumption unclear, not fully warranted, wrong, and so forth. Writing is the chief mode of communicating in philosophy: if you want to demonstrate your understanding to a professor, if you want to relate an abstract idea to your own experience, if you want to persuade someone that your position is the correct one…

Essays Many of us enter university without having learned the skills needed to write a good philosophy paper or essay. Learning these skills is incremental (moving, for example, from writing a paper that seeks to explicate an issue and relevant arguments, to writing a position paper). 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 grind. “Pre-writing”: be sure you understand the assignment. Ask for clarification if you are not sure. Some find “brainstorming” and “free writing” helpful.

Essays Writing is a process, not an end product or a last- minute grind. “Pre-writing” Scheduling: have a plan for when a first draft will be complete (at least before peer reviews in section), when you will return to it to take a closer look, and when you will spend time “polishing” the final version. Revising a paper is one of the few chances we have in life for “a second chance”.

Essays Revising in light of another’s review or your own: Introduction Does it clearly define the topic and forecast the rest of the essay? (yes or needs attention -- with recommendations) Body of essay: Transition from introduction Use of example(s): well executed, appropriate example? Completeness of information (accurate and complete explication of an argument) Conclusion Transition from body of essay Summation CLARITY, CLARITY, CLARITY

Part II Logic Puzzles (Mental gymnastics before we approach Hume!)

Part III Hume’s Problem of Induction

Inductive reasoning  Science and we assume causation (cause and effect relationships)  For empiricists, all the evidence there is for empirical knowledge concerning “matters of fact,” including scientific knowledge is sensory experience  For some empiricists – including Hume – we move from individual experiences/singular statements to generalizations/universal statements using induction (and we certainly do this a lot) presuming causation.

Empirical generalizations 1. Millions of ravens have been observed and all are black. 2. A non-black raven has never been observed All ravens are black  Are, like other forms of inductive arguments, ampliative – the conclusion goes beyond the premises  Reasoning moves from the past and present to the future  From what has been experienced to what has not  From a finite (however large) set of experiences to an infinite number of occurrences

Hume’s question  What justifies our use of induction?  What warrants our using it?  He believes there are two places to look for such justification:  Our experiences (which concern “matters of fact”)  Reason (which he calls “relations of ideas” and “demonstrative knowledge”). What he means is deductively valid reasoning as we find in mathematics, etc..  And proposes we explore each to see if we can discover what justifies inductive reasoning…

Hume’s question Can reason (demonstrative knowledge) provide the justification? No. There is no necessary connection (as there is in ‘2 + 2= 4) between “I’ve always (and so has everyone else) experienced that X causes Y” and “The next X I encounter will cause Y” It is possible, reason tells us, that despite all previous experiences, in our next encounter x will not cause y!

Hume’s question Can reason (demonstrative knowledge) provide the justification? No. The argument is inductive, not deductively valid. It is ampliative: moving from the past and present to the future, and moving from a finite (however large) set of experiences to the future and an infinite set of occurrences. So reason (as Hume understands it) cannot justify inductive reasoning.

Hume’s question Can experience justify our use of induction? Say, we argue: Induction has worked in the past and present to allow us to predict events/phenomena So, induction will work in the future to allow us to predict events/phenomena. If this reasoning doesn’t justify induction, why doesn’t it? It’s circular: it’s using inductive reasoning to justify inductive reasoning!

Hume’s question Can experience justify our use of induction? Maybe if we add a premise: Say, we argue: Induction has worked in the past and present to allow us to predict events/phenomena. Nature is uniform So, induction will work in the future to allow us to predict events/phenomena. This is a deductively valid argument, so why can’t it solve the problem of induction?

Hume’s conclusions Inductive reasoning is just a habit of ours and cannot be justified on either empirical grounds or through reason. But it seems to be an unavoidable habit, common to young children as well as adults. So the skeptical conclusion – that it cannot be justified – is limited in its actual consequences. We all (including Hume!) will continue to engage in it and should go on living as if it is okay… but realizing, at a philosophical level, that it isn’t justifiable. So, I (says Hume) will go on tonight to have a glass of my favorite wine, listen to my favorite music, assume the sun will rise tomorrow, and so forth…

Salmon’s physics student who is also studying Hume!  First hypothesis: Hume’s problem is not any longer a problem as those “secret powers” he refers to (for example, why bread nourishes us) are now known.  Given that we now know many causes he didn’t know, we also know why inductive reasoning from past and present to future, from a finite number of cases to an infinite number, is justified.

Salmon’s physics student who is also studying Hume!  Second hypothesis: Hume’s problem is not any longer a problem because since his time, we have discovered many laws of nature: conservation of energy, conservation of momentum, etc. which allow us to predict (correctly) the outcome of any and all relevant experiments and occurrences.  His professors in physics and research assistants have shown him many experiments that demonstrate the laws are true and without exceptions!

Salmon’s physics student And given increased knowledge in a variety of sciences, we now know that the argument: 1. On every day in recorded time, the sun rose (and on days before recorded time, if it had not, organisms would have died and we could verify that). 2. Physics and astronomy explain why the sun always rises So, the sun always rises (or will rise tomorrow) is deductively valid.

The physics student’s professors His philosophy TA: did your physics professor say that the laws of conservation of energy and momentum are, by their nature, inviolable, or that there are no known exceptions? The latter! His physics professors to whom he asks “Is it possible that any or all of these laws will stop holding tomorrow or on some future date?” Their answer: Yes. There is no guarantee, based on either all of our experiences or our theories, that nature will continue to behave the way it has in the future. We believe it based on faith.

What to think of the problem of induction? Many have worked to develop probability theories so as to be able to replace “provable” with “probable to some degree or other” as useful in evaluating empirical/scientific theories. Strictly speaking, the probability of a generalization or universal statement (of which hypotheses and theories are kinds thereof) based on a finite number of occurrences/events – however large – is zero. But if we don’t assume anyone can have a goddess’s eye view, we can settle for a less exacting understanding of probability.

What to think of the problem of induction? Can evolutionary theory and/or cognitive science help with the problem? Suppose, as they propose and seems reasonable, that for our ancestors, classifying plants, animals, other humans, and physical events brought helpful order to their world view and enabled them to make predictions (“Don’t go near tigers when they’re hungry or you, like our friend Joe, will be their lunch”) that enhanced their survival.

What to think of the problem of induction? Can evolutionary theory and/or cognitive science help with the problem? Well it would explain the habit Hume described, but would it justify the use of induction? No, as it remains the case that there is nothing we can point to in terms of our experiences or theories that guarantees that nature will remain uniform Even in the next fifteen minutes. So we might need to settle for explanation rather than justification of inductive reasoning.