Friday, January 30, 2009

An argument for libertarian free will

The following homely, unoriginal, and obvious argument seems not be a hot part of current discussions, but I've just been struck by the obviousness of its soundness. Start with the following obvious fact:

  1. If I am to any degree responsible for a decision or mental state E, then either E is identical with or the result of a libertarian free choice by me, or E is at least in part the result of an earlier decision or distinct mental state for which I am to some degree responsible.
Add the following very plausible premises:
  1. I have made only many finitely many decisions and have had only finitely many distinct mental states.
  2. There in fact are no causal circles.
It follows from (1)-(3), perhaps with some tweaks (I'm being rather rough here), that if I am to any degree responsible for any decision or mental state, then I have made a libertarian free choice.

Thursday, January 29, 2009

Propositional logic

I am now teaching Fitch-style propositional logic proofs with and, or and not. I had some fun last night and wrote a fun little proof generator in perl (or, perhaps more precisely, modperl). This morning I'm going to teach the students the simple brute-force method that the code uses (basically, just go through all the possible combinations of truth values), which I assume is pretty standard. While the method tends to generate proofs that are unduly long, I think there is a value in having a method that is guaranteed to work even if one is suffering from prover's block. Besides, the algorithm makes it intuitively clear why truth-table completeness holds for propositional logic.

I was going to post a link to a web service that runs the prover. But I then thought that a student at another institution might cheat with it (even though the proofs generated have a somewhat identifiable look, and there is always the risk of bugs in my code), and so I didn't do it. If you're a faculty member, or are someone I know and trust, and are curious to see the code run, email me and I might send you a private link. Of course, someone determined on cheating can use the source code that I posted, but I bet there is other source code posted online that does things like that.

[The code in the link continues to evolve. For instance, it now does some easy simplifications optionally. - Note added later]

Wednesday, January 28, 2009

Determinism and identity

Consider this argument against determinism: Determinism requires that all future facts follow from the laws and the present state. But the laws of nature make no reference to particular individuals or to haecceities. Thus, the laws underdetermine which particular individuals will come into existence in the future. The laws can only determine what these individuals will be like, cannot determine their numerical identities.

We could use modus tollens on this kind of argument. It is possible that determinism holds and yet individuals come into existence. Therefore, the identity of individuals must be determined by their causal history, if determinism holds. But the only plausible reason to think that the identity of individuals could ever be determined by their causal history is if we think that, in an appropriate sense, identity is constituted by causal history.

Tuesday, January 27, 2009

Some offers

1. Consider the offer: "If you give me a sound deductive argument that I'll give you $1000, then I'll give you $1000." It feels like something has been risked in making the offer. But surely nothing has been risked—neither one's integrity nor one's money.

Or is there really a risk that there is a sound argument for a contradiction, and hence for any conclusion?

2. Suppose Fred is a super-smart being who, while very malicious, exhibits perfect integrity (never lies, never cheats, never breaks promises) and is a perfect judge of argument validity. Fred offers me the following deal: If he can find a valid argument for a self-contradictory conclusion with the argument having no premises, he will torment me for eternity; otherwise, he'll give me $1. Should I go for the deal? Surely I should! But it seems too risky, doesn't it?

3. Suppose Kathy is a super-smart being who, while very malicious, exhibits perfect integrity and is omniscient about what is better than what for what persons or classes of persons. Kathy offers me the following deal: If horrible eternal pain is in every respect the best thing that could happen to anyone, then she will cause me to suffer horrible pain for eternity; otherwise, she'll give me $1. Shouldn't I go for this? After all, I either get a dollar, or I get that which is the best possible thing that could happen to anyone.

Do these cases show that we're not psychologically as sure of some things as we say we are? Or do they merely show that we're not very good at counterpossible reasoning or at the use of conditionals?

[The first version of this post had screwed-up formatting, and Larry Niven pointed that out in a comment. I deleted that version, and with it the said comment. My thanks to Larry!]

Monday, January 26, 2009


Is this objectification? Is it morally objectionable?

Friday, January 23, 2009


One of the interesting questions about Christian moral philosophy is how moral life differs if Christianity is correct from how it would be if atheism is correct. Here is one difference. When I have culpably done wrong, I become guilty of the wrongdoing. The state of guilt is a bad state to be in. (It is good, however, if in addition to being guilty, I feel guilt.) If Christianity is right, then every state of guilt in this life has a potential cure through divine forgiveness. If atheism is right, however, then there will be incurable states of guilt.

There are two plausible ways of guilt being relieved. One of them is making sufficient restitution/satisfaction—as it were entirely undoing the badness of what one had done (I actually don't know if this really removes guilt—I think forgiveness may still be needed—but I don't need this for the argument). The other is accepting or maybe just receiving (it's a really interesting question which) forgiveness. But not just anyone can forgive a wrongdoing—the right person or persons must offer forgiveness. The most obvious thing to say here is that it is only those against whom the wrongdoing was done that can offer forgiveness.

If Christianity is right, every wrongdoing is also a wrongdoing against God. One can then argue that God has the authority to forgive the wrongdoing on behalf of all the aggrieved parties, say because all of the goods of all the aggrieved parties come from God, or because the aggrieved parties' very possibility of being better or worse off is a participation in God, or some such story. If this is true, then every wrongdoing can be forgiven by God, in a way that removes guilt. The defense of an exact account here needs more work, but it is clearly true that if Christianity is right, then forgiveness is possible.

But if atheism is right, then there will be wrongdoings which the wrongdoer cannot make sufficient restitution/satisfaction, whether due to the kind of wrongdoing (e.g., murder or rape), or due to the wrongdoer's lack of power (e.g., stealing money, then gambling it away, and then being unable ever to earn it back). Moreover, some wrongdoings of this sort will be such that it will be impossible to obtain forgiveness for them because the wrongdoings are against non-persons (e.g., wanton environmental damage, torture of non-human animals, etc.) or because for some other reason one or more of the victims are incapable of offering forgiveness (this will be the case if the victim is dead—by the wrongdoer's hand or not—or in a coma or the like). One might think that society as a whole can offer forgiveness on behalf of all victims. But that is implausible. First of all, a society plainly cannot offer forgiveness to someone whose crime was not against a member of that society. If Maxine wipes out an enemy tribe, forgiveness from a member of her own tribe will do nothing to remove her guilt. Likewise, society cannot offer forgiveness for the bulk of the wrong of torturing non-human animals (one might think society can forgive one for the parts of the wrong that consist of brutalizing society, or harming the animal's human friends or owners, but those are not the main wrong). Secondly, while one can argue that all wrongdoings are in a primary sense against God ("Against You, You alone, have I sinned," the Psalm has David praying) who is the first and final cause, and hence God's forgiveness suffices to remove guilt, many wrongdoings are clearly only secondarily wrongdoings against society.

This is not an argument against atheism or for Christianity. It is merely an observation of an important difference between the two. My feeling is that non-religious moral thought, however, mitigates the difference by not taking guilt to be as significant as Christianity takes it. But that mitigation is mistaken.

Wednesday, January 21, 2009

An argument against theistic determinism

A pattern of argument against determinism that is worth exploring is not to argue that free will is incompatible with a variety of determinism, but instead to argue that some other feature of our moral life is incompatible that variety of determinism. For instance, the following argument is valid:

  1. If theistic determinism holds, then all our character features, histories and choices are entirely determined by God. (Premise)
  2. If x's character features, history and the choice to promise p to y, are entirely determined by y, then x's promise of p to y is invalid (and hence non-binding). (Premise)
  3. One only validly promises something if one chose to promise it. (Premise)
  4. Therefore, if theistic determinism holds, no promises to God are valid (by 1-3).
  5. Some promises to God are valid. (Premise)
  6. Therefore, theistic determinism is false. (By 4 and 5)

I think one can use (2) in an argument for incompatibilism. You start with (2) and add the premises:

  1. If x freely promises to y something permissible, then x's promise is valid.
  2. If some free choice can have an ultimate cause outside one, then a freely made promise of something permissible to any person whatsoever can have an ultimate cause outside one.
  3. Whether an action is free does not depend on conditions a hundred years before one's conception.
Then, you use a variant of this argument.

Tuesday, January 20, 2009

Liar in three sentences

  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored blue.
  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored purple.
  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored green.

I assume that I will post nothing else in green, blue or purple on January 20, 2009.

What do we have to say about the above three bulleted sequences of text? First, I think that whatever we say about any one of them, we say about all of them—the situation is symmetric. One might try to distinguish between them in terms of the order in which I wrote them, but I could have written them all at once (with two hands and a foot) on the outside of a drum, with no inherent order. So, if we assign a truth value to any one of the three, we must assign the same one to all three; if we say any one carries a meaning, we must say that all three do, and the meanings have to be very similar.

So what can we do? If we say (1)-(3) are all true or that they are all false, we arrive at a contradiction, at least on the obvious interpretation of the texts. Assuming, as we ought, classical logic, no other truth value can be assigned. (And if we have a non-classical logic with a truth value V distinct from true and false, we will still run into trouble as long as we can make the inference from "s has truth value V" to "s is not true".)

Thus, none of the three has a truth value. Since every sentence that expresses a proposition has a truth value, none of the three claims expresses a proposition. But here is an oddity. If none of the three claims expresses a proposition, then I haven't posted anything true in green, blue or purple on January 20, 2009, since only something that expresses a proposition can be true. So it seems that if none of the three claims expresses a proposition, then all three claims are true, which is absurd.

But let's slow down. We have seen that we must say that no one of the three colored claims above can express a proposition that is true. Assuming I post nothing else in the relevant colors, it does indeed follow that:

  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored blue.
  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored purple.
  • No January 20, 2009, post by Alexander Pruss contains a true sentence colored green.
It seems that from this we should infer the truth of each of the colored statements, and then we are in trouble. But here we are either confusing types and tokens, or else we are implicitly using the following principle:
  1. If two written textual sequences are orthographically equivalent, they are semantically equivalent (so if one has a truth value, the other has the same truth value, and so on).
Two sequences are orthographically equivalent provided that they are equivalent according to the rules for making inscriptions in the language—two sequences in a language using the Latin alphabet are "orthographically equivalent" provided that they are tokens of the same sequences of letters and symbols (perhaps in different font, color, etc.)

Now, (1) is in fact false—the cases of homonymy and indexical sentences show this. So we need a weaker form of (1), restricted to "nice" sequences, i.e., ones lacking indexical expressions and where homonymy is not an issue. Let that be (1*). What our argument so far has shown, and I think there is really no way of disputing this within classical logic (and some non-classical ones as well) is that if (1*) is true, then each of the initial colored sequences is true. Since the latter leads to a contradiction, we must either deny (1*) or affirm that the colored statements are indexical or homonymous in a hidden way. Neither of these two moves is plausible. But either move is better than contradiction, and we must make at least one of the two moves on pain of contradiction.

I think what I said so far cannot really be disputed by a reasonable person (adopting a non-classical logic is unreasonable, since it is adopting an incorrect logic). What I will say now, however, will just be speculation. Let us take at face value the fact that the corresponding colored and black sequences lack homonymy and indexicality. It follows, I think, that the truth of a sequence of symbols, even in non-indexical cases, is not a function of the sequence type, but of the sequence token. We have the same sequence type in black being true and in green not being true. This suggests that semantic approaches that quickly leap from sequence token to sequence type are mistaken. It is the token that expresses a proposition, not mediated by the type's expression of anything.

This suggests that linguistics should be done in terms of tokens, not types.

There is still a puzzle as to why the green, purple and blue tokens fail to express propositions, while the corresponding black ones express true propositions. But a puzzle does not suffice for paradox. We would like to have a general account here. My suspicion is that a general account is not available, because language is a lossy encoding of thought, and has meaning derivatively from the meaning of the thought, and one cannot recover the thought algorithmically from its lossy encoding (but in many cases we can make a very good guess). And to have a thought is harder than people imagine it is. This is a lesson from Spinoza and the Tractatus. (It may even be the case that there is something true in the vicinity of Spinoza's radical idea that to have a belief that p, one must know that p. That would be a weird direction to have to move in.)

[I fixed one false to a not true, and some minor typos.]

Monday, January 19, 2009

Observing log: January 18, 2009

For some odd reason, it was noticeably darker than usual at my observing location (about ten miles outside Waco). I wonder if there is some reason why fewer Wacoans would have had their lights on last night? And the transparency was great. I bagged M 1, 31, 32, 35, 42, 43, 44, 51, 65, 66, 76, 78, 81, 82, 97, 108, 109, 110, NGC 136, 457, 891, 1232, 1501, 1502, 1973, 1975, 1977, 1980, 1981, 2023, 2071, 2158, 2194, 3034, 3628, and Hyades. It was marvelous. Some of these were things that I wasn't planning on observing, but I happened on them (e.g., when searching for 1502, I came across a little planetary nebula—it turned out to be 1501). My one regret is that while I was going to go after the nebulosity in the Pleiades, I forgot to put it on my to-observe list before leaving home, so I didn't do it. Four reflection/emission nebulae around the Orion Nebula were lighting up nicely, so I probably had a chance.

Ave regina caelorum!

Salvation of small children

It is tempting sometimes, when defending a position, to sweep certain cases under the rug, saying they are exceptional, or that they are troublesome for the competing positions. This may sometimes be an appropriate thing to do, but it is something a philosopher or theologian should not feel too good about. If my semantic theory is incompatible with, say, some obvious fact about the Liar Paradox, my semantic theory is, well, false. Sometimes one may hope that some small tweak will get one out of the problem, or that one can add an exception clause. But that is a dangerous thought, for it might be that the problem does in fact show that a completely different approach is needed.

Take the bearing that cases of small children, as well as of those the severely mentally retarded, have for accounts of salvation. Let us suppose that one theologizes and concludes that belief that Jesus is Lord is necessary for salvation. But then one is faced with the case of small children who, as far as we can tell, lack the conceptual resources to have the belief that Jesus is Lord. What can one do? Well, one could bite the bullet, and say that no small children are saved. One could mitigate this, then, by invoking a doctrine of limbo. But in fact nobody that I know makes this move. Or one could say that God can miraculously make it possible for a small child that he foreknows will soon die to have such a belief. I have heard one or two people be friendly towards this answer—I myself think it is not that implausible.

But the usual thing to say is just to make an exception of the case, and say that the belief that Jesus is Lord is necessary for salvation, except in the case of children and mentally retarded individuals. This is not a solution one should feel good about, though. First of all, as soon as one starts introducing some exception clauses, one should start worrying whether there aren't more. Secondly, one worries about continuity between exceptional cases and non-exceptional one (intellectual maturation seems to be a continuous process). But, perhaps most importantly, one should look for a unified theory that takes care of the exceptional cases.

There are, in fact, unified theories for this problem. Here is one. What is necessary for salvation is that one believe the Christian teaching to an extent proportionate to one's capacities. One thing that appeals to me about this formulation is that it does not simply let infants off the hook. It lets them off the hook, while increasing the requirements for those whose capacities are greater than average. More is asked of those to whom more is given.

And this unified theory, then, very naturally leads to further questions. What if someone's lack of an ability to believe is not due to an internal gap, but due to an external one? Does it, after all, matter whether one is incapable of belief due to internal causes, such as lack of intellectual capacity, or due to external causes, such as brainwashing or not having heard the gospel from someone who wasn't distorting it through living a life incompatible with it? Thus, a unified theory has the advantage of raising further questions, and leading perhaps to the solution of other difficulties.

Sunday, January 18, 2009

Liar paradox

I am attracted to accounts of the liar paradox on which "This sentence is false" does not express a proposition. Here is one line of thought in that direction. Roughly speaking, speaker meaning is essential to language. Unless a scribble or a noise has speaker meaning, it is just a scribble or a noise, rather than a sentence, even if it looks just like a sentence. Now, for a sentence to have speaker meaning, the speaker must either understand something by it, or else must be referring the words back to an earlier speaker who meant something by them. But nobody really has any idea what they are saying when they utter the liar "sentence". Hence nobody is saying anything in doing so, and hence the liar "sentence" is not a sentence.

Thursday, January 15, 2009

Teaching logic

I am teaching logic, for my first time. It's a tools course for grad students, covering the basic logical tools that are of general applicability (plus three lectures on meta-theory): First Order Logic (FOL), basic (ZFC) set theory, basic (Kolmogorovian) probability theory and modal logic, using Barwise and Etchemendy. I've really nervous about the FOL portion, because I've never taken, TA'ed or taught a class on FOL. (There is a joke about how two Jesuits, who taught in a high school, teachers were talking. One says: "Do you know any chemistry?" The other says: "No, I haven't even taught it.") As a mathematics/physics undergraduate, I took a model theory class (with John Bell and William Demopoulos) and did an independent study on topos theory (with John Bell). I then did independent study in category theory and topos theory as a math grad student, and as a philosophy grad student I took an oral exam in logic (covering through the Goedel theorems). It comes by nature to me to approach logic always as yet another branch of mathematics, with languages being an algebraic structure like groups and fields, which can be given a set-theoretic account: "A first-order language is a 12-tuple <L,.,S,C,P,V,a,e,m,o,c,n> such that..." This, however, wouldn't be a pedagogically very good approach for teaching students, and it isn't the approach of Barwise and Etchemendy. (And now that I am no longer a mathematician, I worry that the lucidity of the above approach is illusory, due to an illusion of thinking one knows what one is talking about when one is talking about sets.)

I've found Barwise and Etchemendy extremely difficult to understand. They are apt to say something like that john (I am using bold to render their sans-serif) is an individual constant, Sits is a predicate, and Sits" followed by a parenthesis followed by john followed by a parenthesis is an atomic sentence. And then I get really puzzled. Are the individual constants particular token inscriptions? It seems they are, since they can stand in spatiotemporal relations ("followed by") while types can't. On the other hand, they talk of the same individual constant reappearing in multiple sentences, and that doesn't work if it is a token (I believe multilocation is possible, but, except perhaps for elementary particles, it takes a miracle). So it's a type, but a type that stands in spatiotemporal relations. Weird. And what does an inscription like Sits(john) in the book refer to? Does it refer to the token? No. It refers to some type. But it's made up of several types: Sits, (, john, ). This is really confusing.

I think I finally have two consistent interpretations of the text worked out. But it was hard to get there.

Wednesday, January 14, 2009


Consider the following ordinary form of argument. Risk R1 is less than risk R0. Risk R0 is a reasonable risk to take. Therefore, risk R1 is as well. Typically, R0 is a risk that reasonable people routinely take, without worrying about it. Thus, we might be told that flying is safer than driving, and since (this premise is usually implicit) it is reasonable to risk driving, it is reasonable to risk flying.

This is a bad form of argument as it stands, for two reasons. The first is that it needs to be established that the benefits associated with taking risk R1 are no less than those of risk R0. The second is that even if the benefit claim is true, this only shows that it would be rational to take R1 instead of of R0. It does not show that it would be rational to take R1 in addition to R0. (Thus, it would be reasonable to fly regularly instead of driving regularly. But given that one is driving regularly, it does not follow from the risk-comparison alone that it is reasonable also to fly.)

Here's an example to show the second failure. The fatality rate for Mount Everest climbs is apparently about 9%. Let us suppose that Kenya is a single woman, with no family, and who does not do any job for which she is essential (e.g., she is not an irreplaceable top cancer researcher). It might (I actually doubt it) be reasonable for Kenya to climb Mount Everest, for the sake of the various goods instantiated by the climb, despite the 9% risk of death. But if the above argument-form were sound, it would be likewise reasonable for her to additionally engage in another activity that carries an 8.9% risk of death and has similar benefits. But the argument could then be iterated. If there was some third activity that carried an 8.8% risk of death, it would be reasonable to additionally do that. Therefore, by repeated application of the argument form, we would conclude that if it is reasonable for Kenya to climb Mount Everest, it would be reasonable for her to do climb Mount Everest and do A, B, C, D, E, F, G, H and I, each of which has a slightly lower risk of death than the previous. Let's say the risks are 9.0, 8.9, 8.8 and so on. Assuming independence (not quite right), her chance of surving all ten activities is less than 47%. But it seems that it is only reasonable to engage in a series of actions that one is less likely to survive than not for the gravest of reasons (such as saving someone's life). The sorts of reasons involved in the climb of Mount Everest are not like that, and even having the benefits ten times over is not worth it.

A related, but I think not identical, issue is that benefits need not be additive. The benefit of both A and B need not be the sum of the benefits of A and of B in isolation. It might be more, or it might be less.

Tuesday, January 13, 2009

Mathematical proofs

Once as a grad student I handed in a proof to a logician. The proof was a good proof—by the standards of mathematicians (the proof was of a probabilistic fact, and I had previously published a number of peer-reviewed articles in probability theory, so I knew what I was doing). The logician absolutely hated it and did not think it was a proof.

What a logician means by a "proof" and what a mathematician means by a "proof" are different. I think the difference is roughly this: A mathematician's proof is an informal argument that there exists a logician's proof.

Monday, January 12, 2009

Asymptotic approach to moral perfection

Consider the following Kantian (nevermind whether it's actually Kant's) reason for believing in eternal life: In a finite amount of time, we cannot achieve moral perfection, but moral perfection is a basic aim of ours, and basic aims of ours are achievable. Actually, it doesn't work. For if moral perfection cannot be achieved in a finite amount of time, then moral perfection cannot be achieved by us, at least not without seriously fooling with the metric structure of time (could one have a temporal structure where an infinite life is followed by a further time of life?) For at any given time, the life we have lived is only finite.

So, perhaps apart from weird metric structures on time, the only way the Kantian argument can work is if our aim not moral perfection, but asymptotic approach to moral perfection. But there are two objections to taking that to be our basic aim. The first is implausibility. "Be perfect!" is, to my mind, a very plausible moral goal. But "Approach perfection asymptotically!" seems much less compeling. Suppose one asks "Why?" In regard to "Be perfect!" the answer is easy: as long as you're imperfect, you are doing something immoral, and you have overwhelming reason not to do that. In regard to "Approach perfection!" one can give the same answer—but this answer supports not "Approach perfection asymptotically!" but "Be perfect!" (And if "Be perfect!" is impossible, then we have a refutation of ought implies can. I myself think "Be perfect!" is achievable with God's grace in this life, though rarely achieved and not required for eventual salvation.)

The second problem with "Approach perfection asymptotically!" is that it seems to be a goal that one can rationally put off to another day—and do so forever, thereby ensuring that one does not approach perfection asymptotically. Here is another way to put this. "Approach perfection asymptotically!" has very little to say about what I should do right now. I should not do anything that would set in me a character that would make asymptotic approach not likely. (It does not even follow from "Approach perfection asymptotically!" that I should at any given time try to maximize the probability of eventual asymptotic approach.)

What if, instead, we make the goal be: "Constantly improve morally!" But that goal is too weak. It is satisfied by the following life. Today, George causes pain to a bunny for one hour. Tomorrow, he does so for 3/4 of an hour. The day after tomorrow, he does this for 4/6 of an hour. The day after that he does this for 5/8 of an hour. The day after that, he does it for 6/10 of an hour. And so on. There is constant moral improvement, but no asymptotic approach. Nor will it help to combine "Approach perfection asymptotically!" with "Constantly improve morally!"

So, if I'm right, the moral perfection goal is "Be perfect!" And not just "Be perfect eventually, some day during an infinite life!" For that could always be put off. (Think of someone who would live an infinite life and whose goal was to do a pilgrimage to the Holy Land at some time or other. That goal could always be put off rationally, while acting compatibly with it.) Rather, the goal has to be "Be perfect in this finite life!" Or maybe even "Be perfect now!"

I should note that the perfection I am talking about here is moral perfection, which is the mere absence of vice, rather than the evangelical perfection that calls for, e.g., celibacy and selling all one's possessions. This evangelical perfection is a supererogatory perfection. Being viceless is not supererogatory.

Friday, January 9, 2009

Frank Beckwith's new book

I found Frank Beckwith's new book, Return to Rome: Confessions of an Evangelical Catholic, a gift from Frank (thank you!). I haven't read it yet, but I've glanced through it, and have found it a charming, well-argued and personal book. One thing that strikes me is how many evangelicals, like Frank, who come or return to the fullness of communion with the Catholic Church are so very gracious to their Protestant brethren, and so grateful what they have gained from their years as evangelical Protestants. The grace that led them to full communion, step by step, is palpable in this love and gratitude. I've suggested in an earlier post that one draws closer to non-Catholic Christians by becoming more faithful to the Catholic faith, and this seems to be a case of that. At the same time, the gracious love of Frank's non-Catholic friends also comes through.

Friendships between ecclesially and doctrinally divided Christians have of late been to me a particular case of the love by which one may know Christians. Division may lead to hatred, but division between people committed to Christ is also an opportunity for great love.

Thursday, January 8, 2009

The value of knowledge

Your best friend, Sally, has just been acquitted of murder. A remote acquaintance of yours, Ravi, has a justified true belief that Sally is innocent. Ravi is mistrustful of the legal system and the fact that Sally was acquitted carries no weight. But what does carry weight for him is that he believes his friend Patricia had seen Sally at a McDonald's at exactly the time the crime was being committed (and, no, he never told the authorities). Patricia, however, did not see Sally at McDonald's—she saw someone else who looked like her from the distance (a distance normally sufficient for distinguishing people, but this lookalike was pretty close). On the other hand, you know that Helga really did see Sally at a Burger King at that time, and indeed saw her closely enough that Ravi's report is not a defeater for Helga. So, Ravi does not know that Sally is innocent, while both you and Helga do.

If knowledge has a value over and beyond that of justified true belief, then Ravi is missing out on something of value that Helga has. This would imply that you have a reason out of charity for Ravi to tell him that Patricia did not see Sally, but Helga did. Moreover, you have two reasons out of charity for Ravi to tell him this. One reason is generated simply by the value of replacing a false belief (that Patricia saw Sally) with a true one (that Helga saw Sally). This reason is pretty weak, since the question of who saw Sally is intrinsically pretty unimportant, and while all truth has value, unimportant truths have but little value. The second reason is there if and only if knowledge has a value over beyond justified true belief: this is the value of Ravi's knowing Sally to be innocent, rather than merely having a justified true belief about it.

Oddly enough, I find myself having the intuition that I have a moderately strong reason to ensure that Ravi knows my best friend Sally to be innocent. What is odd about it is that this intuition conflicts with my theoretical views on which knowledge, as compared to mere justified true belief, has only instrumental value (potential to generate more in the way of true beliefs, etc.). When I initially set out the case, I thought I would have the intuition that I only have a weak reason to tell Ravi that he's wrong about Patricia seeing Sally.

Maybe, though, I can reconcile with my intuitions as follows. Maybe the moderately strong reason I have is generated merely by the reason in charity to replace Ravi's false belief about Patricia seeing Sally with a true belief about Helga seeing Sally. It would seem like this belief is fairly inconsequential in itself, and so the reason generated this way would be weak. But maybe the importance of a belief depends in part on the importance of the things derived from it. And since Sally's innocence is important, Ravi's false belief is important. If so, then the case doesn't undercut my theoretical views.

And here's a further intuition: It is very important that Ravi believe Sally to be innocent; the value of his knowing Sally to be innocent, even if greater, is only a little greater.

Wednesday, January 7, 2009

Deep Thoughts XVI

If you don't need it, you can do without it.

Monday, January 5, 2009


The pacifist believes that one ought not engage in problematic violence in war even if all the standard jus ad bellum conditions are satisfied. "Problematic violence" here means the level of violence that is prohibited. Probably few pacifists would think it would be wrong to push violent foreign soldiers away without hurting them. So, presumably, pushing someone painlessly away doesn't rise to the level of "problematic violence." Where the pacifist draws the line may differ from pacifist to pacifist, but I take it that lethal violence, i.e., violence that, if successful, has a high probability of resulting in the opponent's death, counts as problematic, even when the death is not intended. Thus, I take it that the pacifist will be opposed to shooting at an enemy soldier's heart even when one is using double effect and intending the disablement rather than the death of the enemy soldier. This is all stipulative of what I mean by "pacifist".

Question: Can the pacifist consistently permit problematic violence in law enforcement situations?

If not, then pacifism is seriously problematic, since it seems pretty clear that it is practically impossible to have a decent, self-sufficient community enduring over time without lethal violence to contain violent criminals.

But I think the answer to the question is in fact negative. For how could one draw a line between war and law enforcement? When the invading army marches in, burning crops and murdering citizens, they are breaking the victim country's laws. If problematic violence is permitted to enforce the laws of one's territory, it should be permissible to use problematic violence to stop them. But this seems to be a case of war. Hence, some lethal violence is permitted in some wars, contrary to what I stipulated as the view of the pacifist.

Perhaps, though, the pacifist could claim that it is only permissible to enforce a country's laws with problematic violence on the country's subjects, and an invading army does not consist of subjects. But this is deeply implausible. If it is permissible to use problematic violence to stop a citizen wife from murdering her citizen husband, it should also be permissible to use problematic violence to stop a non-citizen woman who sneaked into one's country to murder her citizen husband. Moreover, this should be permissible even if the woman was commissioned by another state to kill her husband. But if we allow that it is permissible to use problematic violence against criminals acting on behalf of foreign states, then there seems to be no way to deny that it is permissible to use problematic violence to stop invaders.

There is, though, a consistent position the someone could hold here: Problematic violence by agents of a state must be confined to that state's territory. This is not a pacifist position by my stipulation of what a "pacifist" is. But it may be thought to be a pacifist position in a broader sense. But I am not so sure. It seems that this is not so much a position against violence, as a position about jurisdiction.

Saturday, January 3, 2009

Practical moral philosophy

This is a follow-up on an earlier post.

There should be a practical branch of human knowledge about how in fact to attain moral excellence and act well. This discipline would be related to theoretical moral philosophy in, very roughly, the way engineering is related to physics. We might call this practical moral philosophy. This is distinguished from applied ethics. For instance, the military sub-branch of applied ethics may tell us, for instance, what it is permissible for us to tell the enemy when we are tortured, but applied ethics is itself primarily a theoretical discipline, and does not give us much help in knowing just how to withstand torture.

Practical moral philosophy subdivides into two studies: (1) how to attain moral excellence and act well oneself, and (2) how to lead others to moral excellence and good action. The study of the second is a recognized part of contemporary philosophy: it is the study of moral education. But the first has not, I think, been sufficiently developed, at least by analytic philosophers. It has, however, been deeply developed within religious traditions, again with a subdivision into the helping oneself (I do not know the name for this discipline, but within the Christian tradition, many of the practitioners of the discipline are called "spiritual writers") and helping others ("pastoral theology"). (A difference is that in the religious traditions the goal can go beyond natural moral excellence.)

It is not completely clear that this is really a branch of philosophy. Perhaps it is a branch of psychology? It is, indeed, related to "positive psychology". Still, it is not just a branch of psychology in that it depends crucially on the ethical judgment of what moral qualities are in fact excellent and what actions are in fact right.

Friday, January 2, 2009


There is something particularly impressive about astronomical objects, such as nebulae and galaxies. Take the Orion Nebula, a stellar nursery, 25 light years across. Yet, a nebula is, as the name indicates, just a big cloud. It is hard to say that it is necessarily much more beautiful than cloud formations in earth's sky lit up by the setting sun. But the astronomic object is more impressive.

Are we wrong to take astronomical objects as particularly impressive? Or is size something objective? (Would the universe bet at all different if everything got a million times bigger, with the laws of nature changing in a compensatory way?) Or is it, perhaps, the impressiveness has a relational component, and things that have much more mass-energy and spatial extent than ourselves are appropriately seen as more impressive? But if so, then when we are impressed by an astronomical object, we are impressed not just by how the object is in itself, but how it is in relation to us. The latter seems phenomenologically somewhat wrong: being impressed by something takes us outside of ourselves, and hence should not be a way of seeing things in relation to ourselves.

Or perhaps astronomical objects are no more impressive than terrestrial ones, but the mistake in our perceptions is not in our finding the astronomical objects more impressive than they are as much as in our failure to find the terrestrial objects impressive. Perhaps we should find the earthly clouds in many ways as impressive as we find nebulae, and grain of sand in many ways as wondrous as a planet? (In many ways, but not in all. For, after all, a planet has much more complexity than a grain of sand, if only because it is made up many more atoms.)

I generally suspect we don't love and appreciate the things around us enough.