This post has grown to ridiculous proportions. I've divided up this too-long discussion into a part 1 and part 2. Part 1 deals with the supposed entailment of determinism from the possibility of time travel. Part 2 deals with the possibility that closed causal loops undermine determinism.
Part 1
It's something of a staple of the literature on time travel that if it's possible, then we must be determined. But I'm not really sure this is the case. David Lewis made this claim in his "The Paradoxes of Time Travel," and it recently appeared in a nice piece in discover by Sean Carroll.
Here's the basic idea: Suppose that I go back in time to prevent the assassination of Abraham Lincoln in 1865. Since Lincoln was assassinated in 1865, it must be that I failed to prevent the assassination. Therefore, it is not possible for me to prevent the assassination, therefore I am determined not to prevent the assassination.
However, it doesn't follow that I am determined to fail or Lincoln is determined to be assassinated just because it in fact happened that he was assassinated. From the triviality, "Que sera, sera," it doesn't follow that what will be necessarily will be. Lewis's and Carroll's conclusion that we are determined does not follow from the fact that some particular thing will happen and even that we know it will happen. I'll explain a couple of terms and try to show why the possibility of time travel does not entail determinism. (Carroll puts this in terms of undermining free will, but that overlooks the compatibilist position that we can be free and determined at the same time.)
Philosophers distinguish de dicto from de re modal claims. Modal claims are claims having to do with possibility or necessity. The claim that I might have been taller is a modal since it is a claim not about what is but about what might be. De dicto modal claims are only about the words and do not involve the essential nature of the thing. Necessarily, bachelors are unmarried, but it is not true that bachelors are necessarily married. It is a matter of definition that for something to count as a bachelor, it cannot be married. But individual bachelors (people who currently meet the definition) are not necessarily bachelors in that they can get married. De re modal claims are claims about the thing and necessary facts about the thing or its essential nature. De re claims have a different scope. There are fewer clear examples of de re modal claims, perhaps none that apply to our ordinary space-time world. The number 2 is necessarily even. Given the nature of the number 2, there is no possibility that it be other than even. It might be that humans are necessarily physical beings if, for example, it is impossible (in some sense) for humans to exist without a physical body.
Given these terms, the determinist position is that our actions are de re necessitated, not de dicto necessitated. The determinist says that necessarily Lincoln dies in 1865, and necessarily, I will not prevent Lincoln's assassination in 1865. However, all we are really justified in saying is that Lincoln was assassinated in 1865, so, necessarily, given that fact, Lincoln was assassinated in 1865. Necessarily, Lincoln, who was assassinated in 1865, was assassinated in 1865. But it is not true that Lincoln, who was assassinated in 1865, was necessarily assassinated in 1865.
This really shouldn't be a surprising result. The present is the future's past, and we don't think it follows that now, on June 29, 2010 I am typing means that necessarily on June 29, 2010 I will be typing. The fact is that Lincoln was assassinated in 1865, but he might not have been.
Or to give a similar example, if I know that I will pass my exam tomorrow, then it is a fact that I will pass it. But it does not follow that necessarily I will pass it. I will but I might not.
Lewis points out that one's preventing Lincoln's assassination in 1865 is not compossible with (possible given the fact that) Lincoln was assassinated in 1865. Thus, I cannot prevent the assassination given that it occurred. But compossibility with all facts is not what determinism requires. Determinism requires that an event's not occurring is not compossible with all prior facts. And that does not render Lincoln's assassination determined, only necessitated by the fact that it actually occurred. And that's a relatively trivial claim. (Although if Lincoln's assassination occurred both in my past as part of my history and my present as I travel to the past, this notion of determinism gets more complicated. I'll try to sort this out below.)
Were I to try to prevent Lincoln's assassination by hiding out in the Ford Theater and leaping on Booth when he attempted to sneak in and assassinate the president, I would fail. Since Booth succeeded, doesn't it follow that I necessarily fail to prevent the assassination? No, it follows that I will fail--in fact, if I attempted to save the President, then I did fail--but it does not follow that I necessarily fail.
It may seem that the philosophical distinction above represents a distinction without a difference. If nothing I try prevents the assassination of Lincoln, then how is that different from my not being able to prevent the assassination at all? More generally, how can all this talk of de re necessity and possibility make sense when the only world we have available to us is the actual world, the world in which Lincoln was assassinated and in which I failed to prevent it? What is the point of possibility and necessity talk at all if the only thing we can talk about is the actual world?
The answer to this question is really too long to take up here. The short answer is that it makes sense of statements such as "I might have been taller," since some such statements are true, whereas others such as "I might have been an octopus," or "I might have been the number 1," are false. Without modality -- talk of possibility and necessity -- there's really no way to distinguish true from false claims of these sorts. Talk of unactualized possibles (things that might occur but do not) is a bit iffy for the empiricists among us, but it is nonetheless coherent. A golden mountain is an unactualized possible--it could exist but doesn't, but a round square is an unactualized impossible--it does not exist because it couldn't. Leaving aside theories of what unactualized possibles are, they have uses and truth conditions in our language.
If we admit that Lincoln was assassinated in 1865 and nothing I do or have done prevented it, then how does my supposed freedom--here taken to mean that it is possible that I save him--make any difference? Well, it doesn't make any causal difference to things that occur (that's partly why unactualized possibles are so puzzling), but such talk still makes sense. When Terry Malloy says, "I coulda been a contender," he regrets not actualizing a possibility even though it's a fact that he never was a contender. Had he said, "I couldn'ta been a contender," there would be nothing to regret.
But in cases in which there is a possibility of success, and in which I do not know the outcome, I can still attempt to act. There may be multiple possible things I can do this afternoon, and it makes sense for me to decide which of them to do even though necessarily whichever one I do is the one that I do. My actions render some possibility actual, and leave others as unactualized possibles, but the fact that that fact is not enough to render me unfree.
Note that I am not arguing for the existence of free will or the ability to do otherwise than we do even though I had to make some of my points hypothetically by supposing that I might have acted differently. I do not necessarily think we have free will or are not determined; I'm merely pointing out that such possibilities are consistent with time travel. I'm just claiming that the argument from the possibility of time travel does not establish that we are not free and cannot do otherwise. To say that necessarily we will do as we do, does not entail determinism, that we will necessarily do as we do. To put my point more succinctly: determinism cannot follow from the trivial logical point that necessarily everything that happens happens, and that's all that the possibility of time travel really shows.
Part 2
Carroll talks about closed time-like curves or what Lewis calls closed causal loops. (The classic example is Robert Heinlein's "All You Zombies.") Carroll thinks if these are possible then determinism is not true.
Here's an example of a closed causal loop. One day (call it time t1) I receive a mysterious visitor who gives me instructions for how to build a time machine. I build the time machine (completed at time t2) and go back in time to give myself instructions on how to build it. (In fact, if I'd been lazy, I would have just left it around for myself to find so I wouldn't even have to bother building it as long as I remembered to leave it for myself in the past when I was done with it.) Now, everything in this story is consistent and potentially deterministic. We can suppose that everything in my brain is determined, and there is a complete causal story governing my acquiring the plans, building the time machine, and using it to give myself the plans at t1.
Carroll thinks, however, that if this sort of thing were possible, it would undermine determinism. Determinism, on his view, is the idea that everything that occurs at some time is necessitated by the state of the universe before that time, so that necessarily, if the state of the universe is such and such at time t0, necessarily so and so will occur at time t1. The problem I, the time traveler, create for determinism is that my receiving the plans at t1 (and all my work after that) are not determined by the state of the world at t0 but by the state of the world at t2 when I (deterministically) decide to travel back in time to give the instructions to myself. Thus, causation backwards in time occurs and determinism is undermined.
This kind of causation does violate our ordinary sense of causation and determinism. However, I'm not sure we should conclude that this alone could undermine determinism. Here's an admittedly imprecise analogy: Two particles P1 and P2 exist in two systems S1 and S2. P1 and P2 interact within these systems according to deterministic laws. However, P2 now comes into contact with P1, and P1's movement suddenly is no longer determined simply by the laws and the other parts of S1, it is also determined by P2 (and I suppose by its interactions with S2). It doesn't follow that P1's movements are not determined, just that they are not completely determined by system S1. In ordinary terms, we could just describe S1 and S2 as being part of a bigger system, and so that system would determine P1's motion. In the time travel case we have a system S2 that is in the future, so it cannot be described as part of the same system at the same time with S1. I think all this means is that we have to expand our concept of the system that determines P1 to include future events provided there is a time-line connecting P2 from the future to P1 at an earlier time.
David Lewis talks about personal time-lines as a way of making sense of the backwards causation we would get in time travel. The causation along the time-line is not backwards even though it is backwards from outside the time traveler's time-line. Just as special relativity made us give up the concept of absolute simultaneity, time travel would require that we give up absolute past, present and future. And as long as all personal time-lines are deterministic, then the system as a whole could still be counted as deterministic even though we could no longer define an event as determined in the intuitive way as "necessitated by everything that happened before time t1". We would have to modify it to something like "necessitated by everything that happened before time t1 on all time-lines causally interacting with that event."
So, again, I'm not sure that the possibility of time travel by itself entails or contradicts determinism.
Tuesday, June 29, 2010
Wednesday, June 23, 2010
William James, The Will to Be a Self-Deceived
Theists almost invariably proceed from study of arguments for the existence of God—the cosmological, ontological and teleological arguments—to focus on epistemology. Having failed to prove the existence of God given accepted standards of evidence, they change the standards of evidence. Their belief becomes rational by altering what it means for a belief to be rational. Unsurprisingly, when the standards are lowered for religious belief, they must either be lowered for every belief, which leads to obvious cases showing the new standards are too low, or that lowering must be limited to just theism and thus involve special pleading.
One philosopher who offers a lower standard for rational belief is William James. I started writing a long post on faith and reason and got distracted rereading William James’s “The Will to Believe”. This article, or an excerpt of it, appears in almost every introductory anthology on philosophy, and James is widely respected for his work both in philosophy and psychology. So, it is surprising that he would reason so poorly, but the fact is that James’s reasoning has no real merit and is just a rationalization for his preexisting religious belief.
The conclusion of James’s argument is that it is rational to believe in God or religion even though we do not have sufficient evidence that God exists. It is sometimes rational to believe even if you do not have sufficient evidence, and James thinks we do not have sufficient evidence for religious belief. Note that I will be discussing rationality of belief with insufficient evidence rather than rationality of belief when there is sufficient countervailing evidence. The latter is often part of religious belief, and such a view would be more problematic even than James’s, but it is not my target here.
After introducing the issue, James sets up W.K. Clifford as a foil who argues that “it is wrong always and everywhere to believe with insufficient evidence.” James points out that there are two distinct epistemic goals: acquiring true beliefs and avoiding false beliefs, and that Clifford focuses entirely, in this passage, on avoiding false beliefs and never considers the goal of acquiring true beliefs. This is a good point and argues in favor of stating Clifford’s evidentialist (as we call it) claim more positively as well as negatively. For example, one might follow David Hume’s language and say that we should “proportion our beliefs to the evidence”—for example, assenting when there is sufficient evidence and withholding assent otherwise. But that is not James’s strategy.
The irritant in reading James is that he cannot refrain from irrelevant ad hominem attacks on Clifford, James calls Clifford “nervous” and cites his “fear” of making errors and contrasts this fear with his own hopefulness. But the issue is not Clifford’s emotional state; the issue is whether it is responsible for one to believe something when there is insufficient evidence to think it’s true. More importantly, however, James’s remedy for Clifford’s oversight is far too broad: he counts beliefs as rational when it’s obvious that they should not be. Put another way, a serious consideration of Clifford would involve working on the project of what counts as sufficient evidence given the two distinct goals of rational belief. However, James does not of that; James does not offer standards of sufficiency that approach some ideal compromise between acquiring truth and avoiding falsehood. James wants us to believe when we do not have sufficient evidence, but only pragmatic reasons, to think a claim true. Clifford criticizes those who believe with admittedly insufficient evidence, and James defends them. But James’s considerations are so broadly applicable, that all sorts of patently irrational beliefs count as rational on his account. Perhaps that should be the point of the post today, but I’ll put that aside for another time. For now, I want to note that the flaws James claims to find in Clifford’s position are not as great as James believes.
The problem with sufficiency:
James thinks that we do not have sufficient reason to believe any, or most, of the beliefs that are most fundamental and necessary to our interactions with the world and others. We do not have sufficient reason to believe in the value of democracy and progress or the truth of science or the love of others. And so, we must make a guess, one that helps us survive in our society, take a leap of faith and believe—in democracy, in science, in our loved ones—and in so doing we will benefit ourselves and others, and by our faith we may even make our beliefs come true.
Everyone in our society, James argues, takes certain assumptions for granted, and most of us really have no sufficient reason to think these assumptions are true. Indeed, often the critics of these standard views are better justified in their rejection than we are in our acceptance. For example, Sarah believes that humans landed on the moon. She has never given much thought to the belief, but it is simply part of the background set of beliefs that comprises her social inheritance. She has been told it and taught about it so often that she does not consider that it might not be true, and she cannot consciously bring to mind any evidence that might be used to prove that the moon landing indeed happened. Fred, on the other hand, believes that the moon landing was a hoax and is familiar with the evidence put forth in a documentary on Fox asserting that it was faked. Now Fred can debate with Sarah and reduce her to stuttering disbelief and incoherence by demanding explanations for some supposedly anomalous facts about the videos of the moon-landing. Sarah cannot refute Fred, and Fred can rebut any piece of evidence that Sarah manages to assert. So, isn’t Fred the rational one and Sarah the irrational one? Sarah believes without sufficient evidence, and Fred has evidence of a kind. Yet we think Sarah is right to have the belief she does, and Fred is wrong. How can that be unless it is sometimes acceptable to believe with insufficient evidence?
Here’s how: Sarah’s belief is based on the testimony of multiple authorities who are in a better position to know than she is. Her history teachers who taught her about the moon landing and the textbooks she read are based on the authority of people in a position to know whether the moon landing was real or not. And because she believes based on that authority (even though she may not consciously be able to appeal to that authority in her debate with Fred), she is basing her beliefs on sufficient evidence. Even if she did not learn this information from the reliable sources of teachers and textbooks, it’s likely that her belief is better off than the Fred’s since his arguments, while they might seem compelling to the uninitiated, are not in reality convincing to those with some legitimate knowledge. At worst, supposing Sarah’s belief came from others who were not authorities, did not gain their information from authorities and whom she could not reasonably expect to be authorities, Fred’s belief, since it is based on fallacious reasoning, is no better justified than hers.
James overlooks legitimate forms of justification in claiming that our ordinary beliefs are not based on sufficient evidence. He acts as though legitimate appeals to authority do not exist and that, if they do, we have to be able to consciously state our reasoning in those terms. But this is not how all, or probably even most, justification works. We may have little idea how our eyes work, but we still can know beliefs we form on the basis of our first-hand observation. We may not be able to refute the objections of the skeptic—just as we cannot prove that Descartes’ evil genius does not exist—but it does not follow that our beliefs based on authority or the senses are not sufficiently grounded. James is too skeptical here; he rejects legitimate sources of knowledge and justification.
Our belief in the truth (or justification) of science is similar to the moon-landing case. Not all areas have real authorities, as science and history do, so in those areas the justificatory link breaks down. We are then left with nothing more than an appeal to popularity and no sufficient justification. For example, if we believe in God because everyone around us does, this belief is fundamentally different, although perhaps psychologically indistinguishable to Sarah, from the belief in the reality of the moon landing. People observed and participated in the moon landing and the enormous amount of labor and technology necessary to bring it about; there were intersubjectively verifiable first hand observations and accounts connected to the moon-landing. No one has observed God in a way that could be verified by others in the same position to know; no one is in the kind of authoritative position with respect to God that many are in with respect to the moon landing.
Democracy and progress may be a different matter since this involves normativity (facts about what should or ought to be the case) and there are supposed to be no authorities on normative claims. However, there may certainly be sufficient historical evidence for the improvement of the human condition measured as objectively as possible. So, while it is not necessary for my claim, I think a measured respect for democracy as an instrument of human progress is based on sufficient evidence. The important point is that many claims about politics and history are justified by sufficient evidence.
The third case struck me as particularly out of date. James asks us to consider the man who, through his fervent belief that a woman loves him, despite that belief’s lack of foundation in sufficient evidence, convinces the woman that she does in fact loves him. To the modern ear (mine, anyway), this sounds more like stalking and harassment than it sounds like rational behavior. But, being charitable to James, we suppose that there are steps we can take to engage others socially that, he thinks, do not make sense if we are awaiting sufficient evidence that the other person wishes to engage us socially as well. James imagines the rationalist standing aloof from others awaiting their commitment before making overtures of friendship. But that rationalist must be left out in the cold since none would befriend someone so cold and uncaring.
James’s case here is a strawman, however. We all recognize, based on evidence, that people are basically friendly, and that making friends with people often involves politeness and even overt friendliness. There is nothing irrational in thinking that such gestures are more likely to be returned with friendship than is cold aloofness. Must I believe, with insufficient evidence, that someone is my friend or loves me before I proffer my own friendship or even love? Not at all. I only have to believe, based on sufficient evidence, that such overtures are more likely to be received positively than no such overtures, and that the probability of a positive response and the benefits thereof outweigh the meager costs of being friendly myself (or the higher cost of declaring my love).
There is one further type of case, related to the “faith makes it happen” case, and that is when belief would allow for a positive result when the evidence does not render such a belief rational. I may believe irrationally that I will survive my heart attack, and this belief increases my chance of survival, but if I looked rationally at the evidence, I would conclude that I would not survive. Assuming I took all the actions that someone preparing to die should take, and it is by no means certain that I would since doing so might lessen my irrational belief in my own survival, this would make a genuine case in which my being fully rational would have a worse outcome than the alternative.
However, the problem is that, when you take a standard of belief with insufficient evidence, you cannot limit your belief to just these cases. You cannot know that you are in this position if you base your beliefs on insufficient evidence. And if you base your beliefs only on sufficient evidence, it is too late for you to take advantage of the power of positive thinking here; you already have recognized your low probability of survival. The problem is that, for the small increase in probability of survival in a small number of marginal cases, you have to give up rationality in too many other cases. On balance, belief with insufficient evidence would lead to far more harm than good. The possibility of a gain in an unusual case does not justify reasoning in this way in all the other cases in which it would cause harm. And there’s simply no way to compartmentalize the cases in which the belief with insufficient evidence is ultimately beneficial from the much greater number of cases in which the belief based on insufficient evidence is harmful.
In sum James’s examples do not prove that belief with insufficient evidence is necessary. They simply do not support the idea that we cannot survive if we base our judgments only on sufficient evidence.
This leaves me to respond to James for one further criticism of Clifford. James says that he cannot refuse to believe unless he has sufficient evidence because he thinks: “a rule of thinking which would absolutely prevent me from acknowledging certain kinds of truth if those kinds of truth were really there, would be an irrational rule.”
James is trying to make his case more plausible by redescribing Clifford’s advice in a way that overlooks its most salient feature. There really is no problem with following a rule that would “absolutely prevent me from acknowledge certain kinds of truth”. For example, there are certain kinds of truths (although I don't really know what a "kind of truth" is--the issue is the conditions under which one accepts the belief, not the "kind of truth" it is) one could have access to by hitting oneself on the head with a baseball bat (or by using dangerous drugs or exposing oneself to radiation or experimental brain surgery or joining a dangerous cult). Surely, it is possible to come to have true beliefs by hitting oneself on the head with a baseball bat that one would not have otherwise. I might, rationally, come to believe that hitting myself in the head is painful, but I might also believe that aliens are stealing my luggage [Thanks, Steve Martin] or that, honest to God, Lynyrd Skynyrd’s Freebird should be the US national anthem [Thanks, Jeff Foxworthy], or that the third planet in orbit around Betelgeuse is inhabited by intelligent arthropods with a dozen limbs. Some of these beliefs may be true, and at least some of them I cannot get without experimenting on myself in physically dangerous ways. Yet if I adopted the rule: “Do not come to have beliefs by hitting yourself on the head with a baseball bat (or the other methods described),” I would be denying myself the opportunity to come to have these true beliefs. However, it is emphatically not irrational to follow this rule; it’s about as reasonable a thing as I can imagine that I should not hit myself in the head with a baseball bat (or use dangerous, mind-altering drugs or . . . ) even if this results in me missing out on some true beliefs. For one thing, I would never know they were true. And for another, this method is stupidly dangerous. So, James’ argument against Clifford, that his rule irrationally excludes a means of acquiring true beliefs, is not convincing. One often should exclude some ways of acquiring true beliefs if it is harmful to acquire them in that way (as Clifford tries to show believing with insufficient evidence must be) and if there is no reliable means to distinguish the true from false beliefs one acquires by that means.
Here’s another rule for belief: Do not believe if there is overwhelming evidence that the belief is false. Overwhelming evidence is not the same as certainty, so some beliefs which we have overwhelming reason to think are false will be true. So, according to James’s reasoning, it is irrational to close off this avenue of acquiring true belief. Thus, according to James, we should not follow the rule: Do not believe when there is overwhelming evidence that the belief is not true. Unfortunately for James, rejecting this rule is plainly irrational.
This post has gone on far too long, and I didn’t manage to address several of the issues I meant to. Perhaps I can return to them later. But the summary of my argument today is that William James makes rather embarrassingly poor arguments in attempting to undermine the need for sufficient evidence before one can rationally believe. None of the cases he uses to show that we need to believe with insufficient evidence adequately support his point. James’s criticism, then, is not itself based on sufficient evidence.
One philosopher who offers a lower standard for rational belief is William James. I started writing a long post on faith and reason and got distracted rereading William James’s “The Will to Believe”. This article, or an excerpt of it, appears in almost every introductory anthology on philosophy, and James is widely respected for his work both in philosophy and psychology. So, it is surprising that he would reason so poorly, but the fact is that James’s reasoning has no real merit and is just a rationalization for his preexisting religious belief.
The conclusion of James’s argument is that it is rational to believe in God or religion even though we do not have sufficient evidence that God exists. It is sometimes rational to believe even if you do not have sufficient evidence, and James thinks we do not have sufficient evidence for religious belief. Note that I will be discussing rationality of belief with insufficient evidence rather than rationality of belief when there is sufficient countervailing evidence. The latter is often part of religious belief, and such a view would be more problematic even than James’s, but it is not my target here.
After introducing the issue, James sets up W.K. Clifford as a foil who argues that “it is wrong always and everywhere to believe with insufficient evidence.” James points out that there are two distinct epistemic goals: acquiring true beliefs and avoiding false beliefs, and that Clifford focuses entirely, in this passage, on avoiding false beliefs and never considers the goal of acquiring true beliefs. This is a good point and argues in favor of stating Clifford’s evidentialist (as we call it) claim more positively as well as negatively. For example, one might follow David Hume’s language and say that we should “proportion our beliefs to the evidence”—for example, assenting when there is sufficient evidence and withholding assent otherwise. But that is not James’s strategy.
The irritant in reading James is that he cannot refrain from irrelevant ad hominem attacks on Clifford, James calls Clifford “nervous” and cites his “fear” of making errors and contrasts this fear with his own hopefulness. But the issue is not Clifford’s emotional state; the issue is whether it is responsible for one to believe something when there is insufficient evidence to think it’s true. More importantly, however, James’s remedy for Clifford’s oversight is far too broad: he counts beliefs as rational when it’s obvious that they should not be. Put another way, a serious consideration of Clifford would involve working on the project of what counts as sufficient evidence given the two distinct goals of rational belief. However, James does not of that; James does not offer standards of sufficiency that approach some ideal compromise between acquiring truth and avoiding falsehood. James wants us to believe when we do not have sufficient evidence, but only pragmatic reasons, to think a claim true. Clifford criticizes those who believe with admittedly insufficient evidence, and James defends them. But James’s considerations are so broadly applicable, that all sorts of patently irrational beliefs count as rational on his account. Perhaps that should be the point of the post today, but I’ll put that aside for another time. For now, I want to note that the flaws James claims to find in Clifford’s position are not as great as James believes.
The problem with sufficiency:
James thinks that we do not have sufficient reason to believe any, or most, of the beliefs that are most fundamental and necessary to our interactions with the world and others. We do not have sufficient reason to believe in the value of democracy and progress or the truth of science or the love of others. And so, we must make a guess, one that helps us survive in our society, take a leap of faith and believe—in democracy, in science, in our loved ones—and in so doing we will benefit ourselves and others, and by our faith we may even make our beliefs come true.
Everyone in our society, James argues, takes certain assumptions for granted, and most of us really have no sufficient reason to think these assumptions are true. Indeed, often the critics of these standard views are better justified in their rejection than we are in our acceptance. For example, Sarah believes that humans landed on the moon. She has never given much thought to the belief, but it is simply part of the background set of beliefs that comprises her social inheritance. She has been told it and taught about it so often that she does not consider that it might not be true, and she cannot consciously bring to mind any evidence that might be used to prove that the moon landing indeed happened. Fred, on the other hand, believes that the moon landing was a hoax and is familiar with the evidence put forth in a documentary on Fox asserting that it was faked. Now Fred can debate with Sarah and reduce her to stuttering disbelief and incoherence by demanding explanations for some supposedly anomalous facts about the videos of the moon-landing. Sarah cannot refute Fred, and Fred can rebut any piece of evidence that Sarah manages to assert. So, isn’t Fred the rational one and Sarah the irrational one? Sarah believes without sufficient evidence, and Fred has evidence of a kind. Yet we think Sarah is right to have the belief she does, and Fred is wrong. How can that be unless it is sometimes acceptable to believe with insufficient evidence?
Here’s how: Sarah’s belief is based on the testimony of multiple authorities who are in a better position to know than she is. Her history teachers who taught her about the moon landing and the textbooks she read are based on the authority of people in a position to know whether the moon landing was real or not. And because she believes based on that authority (even though she may not consciously be able to appeal to that authority in her debate with Fred), she is basing her beliefs on sufficient evidence. Even if she did not learn this information from the reliable sources of teachers and textbooks, it’s likely that her belief is better off than the Fred’s since his arguments, while they might seem compelling to the uninitiated, are not in reality convincing to those with some legitimate knowledge. At worst, supposing Sarah’s belief came from others who were not authorities, did not gain their information from authorities and whom she could not reasonably expect to be authorities, Fred’s belief, since it is based on fallacious reasoning, is no better justified than hers.
James overlooks legitimate forms of justification in claiming that our ordinary beliefs are not based on sufficient evidence. He acts as though legitimate appeals to authority do not exist and that, if they do, we have to be able to consciously state our reasoning in those terms. But this is not how all, or probably even most, justification works. We may have little idea how our eyes work, but we still can know beliefs we form on the basis of our first-hand observation. We may not be able to refute the objections of the skeptic—just as we cannot prove that Descartes’ evil genius does not exist—but it does not follow that our beliefs based on authority or the senses are not sufficiently grounded. James is too skeptical here; he rejects legitimate sources of knowledge and justification.
Our belief in the truth (or justification) of science is similar to the moon-landing case. Not all areas have real authorities, as science and history do, so in those areas the justificatory link breaks down. We are then left with nothing more than an appeal to popularity and no sufficient justification. For example, if we believe in God because everyone around us does, this belief is fundamentally different, although perhaps psychologically indistinguishable to Sarah, from the belief in the reality of the moon landing. People observed and participated in the moon landing and the enormous amount of labor and technology necessary to bring it about; there were intersubjectively verifiable first hand observations and accounts connected to the moon-landing. No one has observed God in a way that could be verified by others in the same position to know; no one is in the kind of authoritative position with respect to God that many are in with respect to the moon landing.
Democracy and progress may be a different matter since this involves normativity (facts about what should or ought to be the case) and there are supposed to be no authorities on normative claims. However, there may certainly be sufficient historical evidence for the improvement of the human condition measured as objectively as possible. So, while it is not necessary for my claim, I think a measured respect for democracy as an instrument of human progress is based on sufficient evidence. The important point is that many claims about politics and history are justified by sufficient evidence.
The third case struck me as particularly out of date. James asks us to consider the man who, through his fervent belief that a woman loves him, despite that belief’s lack of foundation in sufficient evidence, convinces the woman that she does in fact loves him. To the modern ear (mine, anyway), this sounds more like stalking and harassment than it sounds like rational behavior. But, being charitable to James, we suppose that there are steps we can take to engage others socially that, he thinks, do not make sense if we are awaiting sufficient evidence that the other person wishes to engage us socially as well. James imagines the rationalist standing aloof from others awaiting their commitment before making overtures of friendship. But that rationalist must be left out in the cold since none would befriend someone so cold and uncaring.
James’s case here is a strawman, however. We all recognize, based on evidence, that people are basically friendly, and that making friends with people often involves politeness and even overt friendliness. There is nothing irrational in thinking that such gestures are more likely to be returned with friendship than is cold aloofness. Must I believe, with insufficient evidence, that someone is my friend or loves me before I proffer my own friendship or even love? Not at all. I only have to believe, based on sufficient evidence, that such overtures are more likely to be received positively than no such overtures, and that the probability of a positive response and the benefits thereof outweigh the meager costs of being friendly myself (or the higher cost of declaring my love).
There is one further type of case, related to the “faith makes it happen” case, and that is when belief would allow for a positive result when the evidence does not render such a belief rational. I may believe irrationally that I will survive my heart attack, and this belief increases my chance of survival, but if I looked rationally at the evidence, I would conclude that I would not survive. Assuming I took all the actions that someone preparing to die should take, and it is by no means certain that I would since doing so might lessen my irrational belief in my own survival, this would make a genuine case in which my being fully rational would have a worse outcome than the alternative.
However, the problem is that, when you take a standard of belief with insufficient evidence, you cannot limit your belief to just these cases. You cannot know that you are in this position if you base your beliefs on insufficient evidence. And if you base your beliefs only on sufficient evidence, it is too late for you to take advantage of the power of positive thinking here; you already have recognized your low probability of survival. The problem is that, for the small increase in probability of survival in a small number of marginal cases, you have to give up rationality in too many other cases. On balance, belief with insufficient evidence would lead to far more harm than good. The possibility of a gain in an unusual case does not justify reasoning in this way in all the other cases in which it would cause harm. And there’s simply no way to compartmentalize the cases in which the belief with insufficient evidence is ultimately beneficial from the much greater number of cases in which the belief based on insufficient evidence is harmful.
In sum James’s examples do not prove that belief with insufficient evidence is necessary. They simply do not support the idea that we cannot survive if we base our judgments only on sufficient evidence.
This leaves me to respond to James for one further criticism of Clifford. James says that he cannot refuse to believe unless he has sufficient evidence because he thinks: “a rule of thinking which would absolutely prevent me from acknowledging certain kinds of truth if those kinds of truth were really there, would be an irrational rule.”
James is trying to make his case more plausible by redescribing Clifford’s advice in a way that overlooks its most salient feature. There really is no problem with following a rule that would “absolutely prevent me from acknowledge certain kinds of truth”. For example, there are certain kinds of truths (although I don't really know what a "kind of truth" is--the issue is the conditions under which one accepts the belief, not the "kind of truth" it is) one could have access to by hitting oneself on the head with a baseball bat (or by using dangerous drugs or exposing oneself to radiation or experimental brain surgery or joining a dangerous cult). Surely, it is possible to come to have true beliefs by hitting oneself on the head with a baseball bat that one would not have otherwise. I might, rationally, come to believe that hitting myself in the head is painful, but I might also believe that aliens are stealing my luggage [Thanks, Steve Martin] or that, honest to God, Lynyrd Skynyrd’s Freebird should be the US national anthem [Thanks, Jeff Foxworthy], or that the third planet in orbit around Betelgeuse is inhabited by intelligent arthropods with a dozen limbs. Some of these beliefs may be true, and at least some of them I cannot get without experimenting on myself in physically dangerous ways. Yet if I adopted the rule: “Do not come to have beliefs by hitting yourself on the head with a baseball bat (or the other methods described),” I would be denying myself the opportunity to come to have these true beliefs. However, it is emphatically not irrational to follow this rule; it’s about as reasonable a thing as I can imagine that I should not hit myself in the head with a baseball bat (or use dangerous, mind-altering drugs or . . . ) even if this results in me missing out on some true beliefs. For one thing, I would never know they were true. And for another, this method is stupidly dangerous. So, James’ argument against Clifford, that his rule irrationally excludes a means of acquiring true beliefs, is not convincing. One often should exclude some ways of acquiring true beliefs if it is harmful to acquire them in that way (as Clifford tries to show believing with insufficient evidence must be) and if there is no reliable means to distinguish the true from false beliefs one acquires by that means.
Here’s another rule for belief: Do not believe if there is overwhelming evidence that the belief is false. Overwhelming evidence is not the same as certainty, so some beliefs which we have overwhelming reason to think are false will be true. So, according to James’s reasoning, it is irrational to close off this avenue of acquiring true belief. Thus, according to James, we should not follow the rule: Do not believe when there is overwhelming evidence that the belief is not true. Unfortunately for James, rejecting this rule is plainly irrational.
This post has gone on far too long, and I didn’t manage to address several of the issues I meant to. Perhaps I can return to them later. But the summary of my argument today is that William James makes rather embarrassingly poor arguments in attempting to undermine the need for sufficient evidence before one can rationally believe. None of the cases he uses to show that we need to believe with insufficient evidence adequately support his point. James’s criticism, then, is not itself based on sufficient evidence.
Tuesday, June 22, 2010
Concentration--A Poem
Brow furrowed in concentration,
He puzzles over the machinery of the world.
What does it do?
How does it work?
Why does it do it?
Nostalgic for a time before the world was so hard,
A time nine months ago,
Before he was born.
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