NOT by Argument Alone

1. NOT by Argument Alone G. Randolph Mayes California State University Sacramento

2. Introduction • The central thesis of this talk is that the process of rational inquiry is not adequately described as the examination of arguments for and against competing views. • Rather, rational belief revision typically requires the interaction of two distinct reasoning processes. • Argument is one; explanation is the other.

3. More introduction • I don’t take this to be a terribly controversial thesis. • Most of you probably do not need to be convinced that explanations play a central role in rational inquiry. • But I think it is also undeniable that we philosophers typically both represent and study rational belief formation as the result argumentation, not explanation.

4. Still more introduction • In other words, I think most of us do not really have a clear idea how explanation contributes to rational inquiry. • So I want to try to get clear on this. • And ultimately I want to show how explanatory reasoning figures explicitly into the great debates of modern philosophy.

5. A standard view • On what I will call the ‘standard view’ a successful argument is one that compels rational acceptance of its conclusion. • (As with most standard views, no actual person may hold this view.) • On the standard view, what compels acceptance of a conclusion is • (a) rational acceptance of the premises; and • (b) rational recognition of the validity (or strength) of the argument.

6. More standard view • This view pretty clearly just piggybacks on the notion of validity. • Just as we say : • If the premises are true and the argument is valid, then the conclusion must be true. • We also say: • If the premises are rationally accepted as true and the argument is rationally accepted as valid, then we are rationally required to accept (or at least not deny) the conclusion.

7. A problem • A small problem arises for the standard view when we notice that it is possible to rationally accept false premises. • Rationalists, like Descartes, hoped very much to show that this is not true. • But today just about everyone recognizes that human reasoning, like human observation, is inherently fallible.

8. More of a problem • What this means, of course, is that it is and always will be possible to rationally accept an argument for a false conclusion. • This in itself does not imply that the standard view is wrong. • It only means that we are sometimes rationally compelled to accept false conclusions.

9. The real problem • The real problem for the standard view can be seen when we consider what happens when rationally accepted conclusions come into conflict. • Suppose you currently rationally accept the following proposition: • My spouse loves me. • But now you learn from a normally reliable source in these matters (i.e., your spouse) that s/he does not love you, and that s/he has in fact never really loved you.

10. Denial • In other words: When the truth is found to be lies and all the hope within you dies… then, what? (Rabbi Marshak quoting Grace Slick in A Serious Man.) • Well, if you are a Freudian you might say that we either accept the new reality, or we go into a pathological state called denial.

11. But denial can be rational • In fact, however, there is nothing pathological or irrational about rejecting new information that tends to contradict previously held beliefs. • In the case just described, it may be quite reasonable to suspect anything from a very bad joke, to blackmail, to a sudden brain disorder, or even that you are hallucinating or having a bad dream.

12. The standard response • How, on the standard view, do we deal with situations like this? • The answer is that we simply examine the arguments. • In the given example, we have arguments for contradictory conclusions (My wife loves me; My wife does not love me.) • We should simply accept the conclusion with the strongest argument.

13. Problems with standard response • Let’s first be clear that this is a good answer for many situations, namely those in which one argument is clearly stronger than the other. • But the truly troublesome (and interesting) situations in life, in science, and in philosophy are those in which arguments for contradictory conclusions appear to be equally good (or bad). • The most vexing of these, because they seem to transcend any possible resolution by argument or ‘pure reason’ Kant called the ‘antinomies’.

14. Just be patient? • As you know, philosophers are not terribly concerned about solving problems in real time. • So our typical attitude in these matters is that we just need to keep thinking on the arguments and in the meantime suspend judgment. • (Which is wonderful work if you can get it.)

15. Things that matter • But when we’re dealing with matters of practical urgency, this isn’t really an option. We need to make up our mind, because action of some sort is required. • To be fair, this fact is not lost on all philosophers. • Whether to believe in God, for example, is what William James called a ‘forced option.’ • Most of our moral decisions have this feature.

16. When argument is not enough • So one way of putting our question is: • What is the rational response to information that • would introduce a contradiction into our system of beliefs; • for which the argument is about as strong as the argument in favor of what we presently believe; • and for which suspending judgment is not a practical option? • What other rational resources do we have?

17. Minimalism • One standard answer to this question goes by the name of ‘minimalism.’ • The basic idea is that how we treat the new information depends on the overall effect it will have on our current set of beliefs. • Minimalism is the view that we should do whatever allows us to best preserve as many of our current beliefs as possible.

18. Conservatism • Obviously minimalism is a conservative strategy. • The basic idea is that, all things being equal, it is rational to prefer to avoid making radical changes to a functional belief system. • The burden of proof is on those who would require the biggest changes. • (If it ain’t broke, don’t fix it.)

19. William James • Conservatism belongs to the pragmatic philosophical tradition. In “What Pragmatism Means,” he wrote • The process here is always the same. The individual has a stock of old opinions already, but he meets a new experience that puts them to a strain. Somebody contradicts them; or in a reflective moment he discovers that they contradict each other; or he hears of facts with which they are incompatible; or desires arise in him which they cease to satisfy….. This new idea is then adopted as the true one. It preserves the older stock of truths with a minimum of modification, stretching them just enough to make them admit the novelty, but conceiving that in ways as familiar as the case leaves possible.

20. Problems with conservatism • But conservatism can not be the whole story, and it may not even be an essential part of the correct one. • It’s not the whole story simply because there can be many different equally minimal changes. Just consider this set of sentences: • Frank is my friend. • Frank deals drugs. • My friends are good people. • Drug dealers are bad people. • This is a clearly inconsistent set of sentences that can be fixed by eliminating either of the first two claims. Both changes are equally minimal.

21. Just say no • Another problem is that conservatism can be implemented simply by always rejecting the new information when it challenges what we currently believe. • This would be the right method for infallible agents, but disastrous for humans. • (It should be noted, however, that we all operate with a strong bias in favor of what we currently believe.)

22. Quine-Duhem • William James’ view of belief revision has much in common with what has become known as Duhem/Quine holism. • One implication of the Duhem/Quine thesis is that our views about the world can not be tested in isolation. • If, for example, you believe there is coffee in the pantry, and you look to find no coffee in the pantry, then on the surface it seems as if the rational conclusion is that there is no coffee in the pantry. • But this holds true only in virtue of a background assumption, viz., that you are competent to detect coffee in the pantry, which itself may depend on the assumption that you have had your coffee.

23. Come what may • Quine (in)famously wrote in “Two Dogmas of Empiricism” that: • Any statement can be held true come what may, if we make drastic enough adjustments elsewhere in the system. Even a statement very close to the periphery can be held true in the face of recalcitrant experience by pleading hallucination or by amending certain statements of the kind called logical laws. 

24. Beyond minimalism • Quine did not conclude from this that every revision that preserves logical consistency is as rational as any other. • Nor did he believe that we should make only the changes that would preserve the “older stock of truths” intact. • Rather, what Quine suggested is that our primary aim should be to preserve the structural integrity of our web of belief. • What WilfridSellars and others subsequently called its “explanatory coherence.”

25. Explanatory Coherence • Philosophers and psychologists have used a variety of terms to characterize the elements of explanatory coherence in structural terms. • But what I want to focus on here is the sense in which achieving explanatory coherence requires us to engage in specifically explanatory reasoning.

26. Explanatory Coherence • The basic idea is surprisingly easy to understand. • First, every proposed resolution to a contradictory set of claims raises specifically explanatory questions. • Second, the preferred resolution is always the one for which the best explanations can be provided.

27. Argument vs. Explanation • Before we proceed let’s take a moment to get clear on what an explanation actually is and how it differs from an argument. • We can get at it through a distinction between two different kinds of questions. • Argument:How do you know? • We request arguments when we do not yet accept a conclusion, and are looking for a rational basis for doing so. • Explanation: Why is that so? • We request explanations when we already accept something as a fact, and are trying to understand why it is the case.

28. Argument vs. Explanation Example • You can make this intuitive by just noticing that for virtually any statement we make about the world we can adopt either an argumentative or an explanatory stance. • Example • My cell phone is broken. • How do you know that? It won’t power up. • Why is that? I dropped it in the toilet.

29. Argument vs. Explanation example • Note how argument and explanation work together in this case. • The explanatory step is distinct, but also helps to solidify confidence that your argument is on the right track. • Without a model explaining how it might have been broken, you will be less confident that it is broken. • Also, if you accept this explanation, it helps to set a rational plan for action.

30. Explanatory Coherence • So, here is what I said before that commercial break. • First, every proposed resolution to a contradictory set of claims raises specifically explanatory questions. • Second, the preferred resolution is always the one for which the best explanations can be provided.

31. Argument vs. Explanation • Before we proceed let’s take a moment to get clear on what an explanation actually is and how it differs from an argument. • We can get at it through a distinction between two different kinds of questions. • Argument: How do you know? • Explanation: Why is that so? • We request arguments when we do not yet accept a conclusion, and are looking for a rational basis for doing so. • We request explanations when we already accept something as a fact, and are trying to understand what causes it to be the case.

32. Example • To see this, consider a mundane example in which the consistency of your belief system is threatened by incoming information: • Your friend Marcie says she’ll call you tonight if she is going to the movies. Marcie doesn’t call. A week later you find out from your mutual friend Claire that Claire and Marcie went to the movies that night together. • This problem can be represented as a contradiction that results from accepting three propositions.

33. Example continued • If Marcie goes to the movies, she will call me. • Marcie went to the movies. • Marcie didn’t call me. • This is an inconsistent set of (we’ll say) equally plausible propositions. It can be repaired by denying any one of them. But which one? • The answer is that the decision to deny any particular proposition generates one or more explanatory questions. We deny the one whose questions we are best capable of answering.

34. Example continued • If Marcie goes to the movies, she will call me. • Marcie went to the movies. • Marcie didn’t call me. • Suppose we deny the first proposition, what explanation question arises? • Why did Marcie say she would call me? • Possible answers: • She intended to call me but forgot. • She intended to call me but decided against it. • She had no intention of calling me, but didn’t want to hurt my feelings.

35. Example continued • If Marcie goes to the movies, she will call me. • Marcie went to the movies. • Marcie didn’t call me. • Suppose we deny the second proposition. • Explanation question: Why did Claire say this? • Possible answers: • Claire mistakenly believes that Marcie went to the movies with her. • Claire wishes to deceive me.

36. Example continued • If Marcie goes to the movies, she will call me. • Marcie went to the movies. • Marcie didn’t call me. • Suppose we deny the second proposition. • Explanation question: Why didn’t I receive the call? • Possible answers: • My phone wasn’t working. • I accidentally had the phone on vibrate and didn’t hear it ring. • Marcie dialed the wrong number.

37. Example discussed • The idea, then, is that we deny the proposition whose corresponding explanation-seeking question(s) we are best capable of answering. • Clearly, what you judge to be the most plausible explanation, depends a great deal on beliefs that you have about Marcie, Claire, cellular networks, your own competence, etc. • Moreover, your acceptance of any particular explanation is subject to further inquiry. • For example, if you decide the best explanation is that Marcie did not go to the movies and Claire is simply lying, you would ordinarily not accept this without a further explanation of why she lied, and finally some independent evidence that she actually did lie.

38. Empirical evidence for this view • Right now I’m representing this as a normative model, but there is evidence that it is descriptively accurate as well. • Recall that the competing model is ‘minimalism,’ that we simply make the changes that preserve the greatest number of previous beliefs. • This view would suggest that people will typically respond to challenges by rejecting particular categorical propositions and preserving generalizations. • This is because when you deny or revise a generalization, it will affect many inferences you may have made with that generalization.

39. Empirical evidence for this view 2 • The cognitive psychologist Philip Johnson-Laird has demonstrated that this isn’t what people do. • E.g., Subjects are presented with a problem like this. • If the student doesn’t stay on task, then s/he stays after school. • Winifred didn’t stay on task. • Winifred didn’t stay after school. • Subjects usually choose to resolve the contradiction by modifying the generalization rather than rejecting either of the singular propositions.

40. Empirical evidence for this view 3 • The explanatory hypothesis predicts this because exceptions to generalizations are common and these exceptons explain the non occurrence of expected results. • In other words, if we do this: • If the student doesn’t stay on task, then s/he stays after school. • Winifred didn’t stay on task. • Winifred didn’t stay after school. • We can easily explain why this is not so in terms of reasonable departures from the rules, such as students whose failure to stay on task isn’t their fault.

41. Empirical evidence for this view 3 • But if we do either of these: • If the student doesn’t stay on task, then s/he stays after school. • Winifred didn’t stay on task. • Winifred didn’t stay after school. • Then we are stuck with what will be very ad hoc explanations of why Winifred appeared not to be on task when she really was, or why she appeared to be kept after school when she really was.

42. Empirical evidence for this view 3 • I should note here that we very often do favor revisions that are minimal. In the following we might actually deny a singular proposition rather than revise a general one: • If you follow this diet, you will lose weight. • Sam followed this diet. • Sam did not lose weight. • But the explanatory hypothesis would tend to predict this as well, since people often claim to follow diets when they don’t, whereas dieting without loss of weight is challenging to explain.

43. The historical part • Ultimately, what I want to claim here is that the explanatory model of belief revision is something that philosophers need to learn to practice in an explicit way. • This is because a great deal of philosophical theorizing results from contradictions arising from sets of equally plausible claims. • We need to recognize explicitly that we are not limited to simply comparing the strength of the arguments for an against the claims involved. • We can also produce and evaluate theories that explain why one of the claims may appear to be true, even though it is not.

44. Knowledge and Skepticism • Consider a crude version of the problem of skepticism about the external world. • 1. Humans have knowledge of the external world. • 2. Knowledge requires certainty. • 3. Certainty about the external world is impossible.

45. Knowledge and skepticism 2 • 1. Humans have knowledge of the external world. • 2. Knowledge requires certainty. • 3. Certainty about the external world is impossible. • A philosophical skeptic doesn’t really need to claim (to know) that 1 is false. Skepticism is really just what happens when you can’t resolve this antinomy. • But if we take the resolution of the antinomy seriously and employ the explanatory hypothesis, it is not difficult to see that the denial of 1 is not even an option. • This is because if 1 is false, no explanatory question that arises from denying 1 can be answered.

46. Knowledge and skepticism 3 • 1. Humans have knowledge of the external world. • 2. Knowledge requires certainty. • 3. Certainty about the external world is impossible. • Classical foundationalists like Descartes attempt to deny premise 3. • Unlike the skeptic, Descartes did not simply infer the falsity of 3 from the truth of 1 and 2. • Rather, he tried to prove that we could be certain that our sensory and intellectual faculties are reliable when used as God intended.

47. Knowledge and skepticism 4 • Descartes was, I think, keenly aware of the explanatory problems associated with asserting that we can know some things with certainty. • Indeed, one of his lasting contributions was to have developed a skeptical hypothesis -the evil demon- that would explain how we could feel perfectly certain about some things even though we are wrong about everything. • Descartes, did not suggest this hypothesis was plausible. But he believed that it had to be ruled out if we were to believe that our subjective certainty was any real basis for genuine knowledge. • And as it turns out, he could not rule it out.

48. Knowledge and skepticism 5 • 1. Humans have knowledge of the external world. • 2. Knowledge requires certainty. • 3. Certainty about the external world is impossible. • The final option is to deny that knowledge of the external world requires certainty. • The main explanatory question that arises here is: How is it possible for an agent to both know that P and accept that P may be false? • There are actually several different interesting ways of answering this question.

49. Empiricism and physicalism • Now let’s consider a related problem, sensory knowledge of the physical world. • 1. We have knowledge of a physical world. • 2. Our knowledge of the physical world is based on our senses. • 3. Our senses do not reveal the existence of a physical world.

50. Empiricism and physicalism 2 • 1. We have knowledge of a physical world. • 2. Our knowledge of the physical world is based on our senses. • 3. Our senses do not reveal the existence of a physical world. • Perhaps the most straightforward way to resolve this contradiction is direct or naive realism. This was Thomas Reid’s position. • But, again, the main problem with direct realism is explanatory in nature. • How can we be directly aware of something that is external to us? For Reid this question is not answerable, because any causal theory of perception would implicitly deny direct realism.