So lately I’ve been reading a bit of Overcoming Bias and Less Wrong. While the posts on these sites are always interesting they frequently, especially at Less Wrong, seem to promote a sort of cult of rationality. Of course I too value reaching the right conclusions instead of the wrong ones and am broadly sympathetic with the goal of ameliorating the negative effects of psychological shortcuts that interfere with our utility but alot of the content on these sites seems to go much further than this. For example consider these posts by Robin Hanson and Eliezer Yudkowsky. Underlying these remarks seems to be the assumption that there is some kind of objective standard of (perfect?) rationality to which we could aspire that would somehow capture our intuitive notion of rationality as distinct from merely being lucky. While I rarely see rationality so earnestly venerated as it is on these two sites the same assumption pervades much of analytic philosophy and many puzzles and papers simply take it for granted that there is some well defined notion of rational thinking/belief(I’ll leave act rationality out of this for the moment). However, despite being an extremely useful tool in describing common situations and deciscions it’s long been my view that, when considered in full generality, rationality isn’t even a coherent concept.

To explain what I mean we first need to go back to Quine’s seminal paper Two Dogma’s of Empiricism. Even though I think Carnap clearly had the better of the argument about analyticity¹ I want to give Quine credit for pointing out to me the way in which the concepts we use depend on our background assumptions (how we model/conceptualize things) for their very coherence. Just as the concept of an equivalence class stops making sense once you start talking about non-transitive relations so too do many of our scientific and everyday notions cease to be well defined when we no longer accept the assumptions they were defined with respect to.

Stealing an example from Quine consider the Newtonian concept of kinetic energy. A good Newtonian physicist would have said that the kinetic energy is defined to be .5mv² where m is the object’s mass and v it’s velocity. However, kinetic energy is obviously also intended to be in some sense a measure of the work it would take to stop that object. Since these two notions coincide on the Newtonian picture there isn’t any problem. So long as we believe (or even use as an approximation) Newtonian physics there isn’t any question as to which is the right definition of kinetic energy. We are simultaneously committed to the concept capturing both notions. What Quine observed is that once we abandon the Newtonian conceptual framework there isn’t really any objective fact about which commitments we should honor and which we should discard. If scientists had responded to special relativity by using kinetic energy to describe the Newtonian formula and started theorizing about the conservation of Eisensteinian smenergy we couldn’t really accuse them of having made a mistake. Just as there is no right way to extend the notion of an equivalence class to non-transitive relations there often isn’t any right way to extend our scientific or everyday concepts outside of the frameworks they were conceived in.

The upshot of all this, in my view, is that our most useful concepts often presuppose certain assumptions. When these assumptions no longer hold the concepts themselves may cease to be coherent. So keeping this in mind let’s take a look at the assumptions that give rise to our concept of rationality.

Without going into too much detail I think it’s fairly safe to assume that a major (primary?) grip on (belief) rationality comes by way of postulating that people hold various beliefs where we take those beliefs to behave in some loose way like propositions. In other words we gloss over complexities like the effect of context and social situation on the views people express and simply pretend they either do or don’t believe some claim. Of course you can embelish this view a great deal and allow people to believe things in varying degrees or even take them to merely have some transitive implication relation. However, we can only stretch these concepts so far before they become unwieldy and useless, something we all implicitly recognize when we hesitate to attribute beliefs to ethnic groups, countries, or our computers.

So what? It’s hardly news that some aspects of people’s behavior won’t be well described by idealizing them as having something like beliefs. However, the point I want to press home is that rationality isn’t a property that big fleshy globs of atoms have. Rationality, is a concept grasped in terms of a certain kind of idealization about human behavior. It’s a useful concept and useful idealization but it’s still a type error to think of it as a property that applies to actual physical beings. We frequently forget this because in most contexts there is an obvious “right” way to idealize someone as an agent with certain beliefs so we talk about people having irrational beliefs and find it useful. However, it’s important to remember this shorthand only makes sense as long as this kind of idealization makes for a decent model of human behavior. Just like it’s simply confused to talk about the Newtonian kinetic energy of a particle traveling at .999c there are situations in which idealizing people as having something like belief is such a bad way to model their behavior that talking about rationality is similarly confused.

But the situation for a viewpoint independent concept of rationality applicable to real people only gets worse once you realize just how sensitive the ascription of rationality is to the way we choose to idealize the situation. Choosing to idealize a split brain patient as a single agent will yield very different judgments about his degree of rationality than idealizing his actions as the result of two seperate agents with distinct beliefs. It’s not that one of these idealizations is wrong and the other right (what could that even mean?) but just that in certain contexts one will be more useful than the other. And it’s not just split brain patients, Frued and many others have often taught that people were better modeled as the result of several competing agents or personalities. To really drive home the dependence of ascriptions of rationality on your choice of model just try to work out how you could make a principled application of the concept to a network of partial autonomous, partially integrated AIs.

My point is that it’s not just that we can’t ever be fully rational. It’s that the very notion as applied to living breathing people isn’t even coherent. Rationality is a concept that lives in an abstract idealize realm populate by agents possesing something like beliefs. It’s only applicable to real creatures insofar as this kind of idealization is useful and people largely agree on how it should be done. Step beyond that and it just doesn’t make sense anyone. I also think this realization can help alleviate some of the confusion over various paradoxes like the surprise quiz but that’s another post.

In philosophy it is common to take strong intuitions about a subject as reason to believe what we intuit as true. For instance in moral philosophy we generally take our intuition that abducting bums and torturing them to death is wrong to weight against any moral theory that concludes the opposite. Now how these intuitions could give us the proper sort of epistemic access to moral facts is a classic problem in meta-ethics and analogous problems are equally famous in areas like philosophy of math, counterfactuals and many more but I want to try to approach this problem a bit differently¹. Suppose you are dosed with a drug and this altered state of consciousness provokes an extremely strong moral intuition. Does this intuition still give one reason to believe it’s conclusion is true? Is it just as good as a sober intuition? If not why not?

For concreteness sake let’s assume that every time you take MDMA² you have an outflowing of love and sympathy which makes the death penalty or any retributive (as opposed to deterrent or preventative) punishment seem to be a horrible moral abomination³. Or even just that you know that if you were to take the drug you would feel this intuition. Now intuitively one wants to say in these cases that such a drug induced intuition doesn’t count or at least counts much less but why? Well one reason we might wish to exclude such intuitions is the worry that there would be too many of them. Indeed if you believe experiences (or whatever intuitions are) supervene on local physical state (e.g. brain state) then your likely to think that some kind of brain intervention could create any moral intuition desired⁴. But this isn’t a (sound) argument that these intuitions aren’t equally valid it’s merely a wish that they aren’t. It would be nice to have access to moral facts but we can’t discredit the possibility that none of our intuitions, drugged or otherwise, give us any evidence just because we don’t like it.

A more promising approach is to observe that we don’t credit the sensory experiences of inebriated people to the same degree we credit those of sober folks and argue that philosophical intuitions work similarly. While this sounds good the problem is that it’s just not true that we always trust sober perceptions more than chemically altered ones. For instance if a perceptual task requires great focus we very well might prefer the observation of someone taking a small dose of amphetamines than that of a sober person⁵. Certainly imagine drugs or other brain alterations that would improve our perceptual accuracy in some ways even while they might impair it in others. Thus it’s not that we have a blanket rule about trusting sober observations more, rather, we merely induct on prior observations about perceptual accuracy in different states. Without an independent check on moral facts we don’t have any reason to take our normal sober brain states as more reliable in this regard than others⁶.

More broadly one might observe that even without knowing anything about drugs or the effects of brain injuries one would probably believe that most modifications to the brain would degrade, rather than improve our perceptual abilities. However, we only believe this because we have reason to believe that evolution has tuned our brain for perceptual accuracy. Given a situation where we have reason to believe evolution would have tuned our perceptions to get an incorrect, rather than correct, result⁷ we should believe that random alterations to our brains would be likely to improve the result. After all if your brain is a reliable mispredictor (when X occurs we perceive ~X) then any alteration in that behavior would have to be an improvement. Thus whether or not we should assign a higher probability to our normal sober intuitions being correct or those induced by brain changes depends on whether or not we have reason to believe evolution favored accurate or inaccurate intuitions.

When our intuitions are not subject to an external check I really don’t think we have any reason to give more weight to our actual intuitions than those we would have if our brains were altered. In the particular case of moral intuitions I would argue that if anything we have reason to believe that our intuitions are, if anything, less reliable than those selected at random. We have plenty of meta-moral intuitions like ‘all people deserve equal moral consideration’ yet there seems to be no shortage of examples where evolution has favored more concrete intuitions in conflict with these principles, e.g., people tend to have different moral reactions when it’s a family member’s life on the line than a strangers. Thus any analysis that gives more weight to our actual intuitions than other possible ones must acknowledge the existence of evolutionary pressures to have inaccurate moral intuitions while their are both in principle (moral facts would seem to lack causal powers) and pragmatic (continued failure to show otherwise) reasons to think there isn’t any evolutionary pressure for our moral intuitions to match up with true moral facts.

I think this actually establishes an extremely strong negative result. In the absence of a plausible naturalized epistemology of morality (or philosophy of math, or knowledge of possible worlds) it’s irrational to use our intuitions as evidence. Without any justification of why our actual intuitions are more likely to be valid than any of those intuitions we could have had it’s an outright error to treat them as stronger evidence for their claims than the fact that we could have had some other intuition. However, even if you aren’t willing to take it this far it raises some very interesting questions. One that seems particularly challenging for the meta-ethicists is the following:

Suppose theoretical analysis (or survey of galactic civilizations) reveals that our moral intuition about the importance of life is actually an improbable fluke and evolution tends to equip any sentient being with the intuition that it’s the future of someone’s genetic line (or their happiness) that is morally salient not whether they live or die. Does that give us reason to believe that death isn’t morally salient? If not how can it be rational to believe something about moral facts on the basis of an accident without any connection to these facts?

Philosophers and stoned college students have long been intrigued by the idea that we could be living in some kind of simulation but I was surprised to see this idea mentioned in the New York Times ¹. The NYT article summarizes this paper by philosopher Nick Bostrom who has also created a webpage with links to background reading, depictions of simulation scenarios in the media² and even someone’s wiki about ’simulism’³. The paper, while interesting and notable for getting into the New York Times, doesn’t say anything really new. It merely fleshes out the argument that if we believe that simulated individuals would have real experiences and that it is likely that humans will create many simulations of humanities past then you should assign a high probability to the proposition that you are actually being simulated.

While my intuition is that the idea behind this argument is correct I think the argument Professor Bostrom gives isn’t quite right. In particular the focus on what human civilizations are likely to do and ancestor simulation seems all wrong. There is no reason why totally alien beings could not simulate people nor to believe that our simulated universe resembles the real one in which the simulation is running much less that we are an earlier stage of the simulators history. Later I might think about how to fix this point but what made me want to write this post was the comment in the NYT that you could get out of the argument by either denying strong AI (a simulation wouldn’t be conscious) or by assigning a low probability to the chances that human beings will progress far enough to run such simulations.

This reminded me of the post I wrote a year ago about Sleeping Beauty in The Matrix arguing that a widely accepted solution to the sleeping beauty problem also implied we should believe the universe creates infinitely many individuals with the same memories and experiences as we have. Of course intuitively I think the conclusion of this argument is total crap but it’s tough to figure out why it’s wrong⁴. In short I think there is something very subtle going on in these sort of arguments that I don’t yet understand. If I ever figure it out I will post but until then I’m remaining skeptical.

So here comes another film inspired philosophical puzzle. Well really a less sophisticated version of this problem occurred to me a long time ago while reading Permutation City by my favorite sci-fi author Greg Egan and seeing someone last week totally consumed with a virtual world reminded me about it but everyone knows what I’m talking about when I mention the matrix. However, some people may not be familiar with the Sleeping Beauty problem so I will provide a short summary in the post body.

The point I want to illustrate is that whether or not this is the actual world or a matrix style simulation is an instance of the sleeping beauty problem. In particular the same reasoning that supports the two-thirds solution to the sleeping beauty problems seems to guarantee we are in a repetitive simulation. I don’t know if this puzzle has appeared in the literature yet (it seems kinda obvious to me so I have a hard time believing it hasn’t) but it is new to me (no I haven’t read all the papers I link so it could be there). Since I find the reasoning supporting the two-thirds solution compelling I expect some other solution will ultimately be forthcoming but I expect that solution will be more interesting than the problem itself.

More concretely it certainly seems possible that we are actually in a virtual world like the matrix. It remains possible even if we suppose that our lives are in fact arbitrarily long (the ‘real’ world has conquered aging) and every time we die in the virtual world our memories are wiped and the simulation is restarted. While we might think ‘a priori’ such a world is unlikely since it seems possible we should assign it some non-zero probability. However, since this matrix world repeats the experience we are having infinitely many times it would seem that the same reasoning which allows us to support the two-thirds solution in the sleeping beauty problem requires that we find the matrix world arbitrarily more probable than our own world, i.e., the probability of the matrix world conditionalized on matrix world or real world is one (or arbitrarily close to one). Of course the virtual world aspect isn’t central to the problem. We could repeat the same argument in favor of Nietchzie’s world of eternal recurrence or any situation which involves making us experience our lives so far arbitrarily many times. (more…)

So I was reading a recent post by my friend Kenny over at one of his blogs about Intelligent Design. In it he takes the New York Times to task for writing a ‘balanced’ piece which makes it seem the scientific explanation of the grand canyon seem no better than an intelligent design type explanation. Since I’m a cheap bastard and not willing to pay the New York Times to see the old article I can’t such much about the article itself, and besides I like to keep my political commentary over at my other blog but I’m sure I would be equally appalled. However, it got me to thinking about whether there is any objective sense in which the scientific explanation is better. Not that I think the attacks on the geological explanation have any merit but even without these attacks in what sense can we say one of two theories which consistently explain a phenomenon is better.

Ultimately the question of which theory¹is better — that the grand canyon is the result of billions of years of geological change or that it is the work of god — is all about how we assign our prior probabilities. Clearly if we assign a very high prior probability to the existence of a god who would make the universe look like it had been created billions of years ago that would be the better theory. This seems exactly what the ID advocates are really doing, the attacks on the scientific explanation being just an after the fact justification.

Most philosophers I know seem to be convinced that ID advocates are not just wrong but somehow objectively wrong in a way which an impartial observer could determine. Yet this would seem to require some objectively correct assignment of prior probabilities like Carnap wished to find and most modern philosophers don’t believe such things exist. Now we could try and turn to some kind of demarcation between science and non-science like Popper offered but this would only tell us something about how we use the word science and not give as an objective reason to prefer one explanation to the other.

To be clear this doesn’t really affect the legal issues of teaching ID in schools. Regardless of it’s objective status we have a certain cultural agreement on what counts as religious belief. However, I thought the situation brought up some interesting philosophical issues and illustrated the reasons I have such a hard time dismissing Carnap’s program. In some sense I really want it to be true since it feels like I have objectively better reason to believe in geology than a divine trick but I don’t know if that is the sort of intuition that is evidentiary or not.

So my friend Kenny has an interesting entry over on his blog regarding Weatherson’s post on knowledge and discovery. Kenny argues that it is merely justified true belief which gives others a reason to believe a piece of knowledge counts as discovery of that piece of knowledge.

I’m skeptical of Weatherson’s analysis of the problem for slightly different reasons than those Kenny emphasizes. I’m skeptical primarily because I don’t think prior true belief is enough to block discovery (a fact Kenny seems to doubt as well). I’m also unsure if justified true belief is even necessary for mathematical discovery or philosophical discovery. I will discuss this question and try and iron out some of the further ambiguities in the ‘discovered blah’ usage. However, the real point of this post is to muse about the relationship between JTB and knowledge in the case of the a priori. Can these two concepts really come apart in situations involving purely deductive reasoning. In particular I will argue that in the Kripke situation under consideration knowledge and JTB simply don’t come apart so while Kenny’s comments may be correct they are mostly irrelevant to this case. (more…)

So I was reading this post over at Brian Weatherson’s blog. In it Weatherson points out quite interestingly that the question of whether a belief should not count as knowledge because it is based on a false presumption is actually quite subtle. Or to put it another way Gettier counterexamples against knowledge in the case of justified true beliefs often turn on the falsity of some justified step in the chain of belief. Weatherson is pointing out that even if your knowledge is based on a false belief in some cases it is still knowledge.

Given the type of examples Weatherson deploys I suggest the answer lies in some application of charity to the believer. Even if the justification an agent is disposed to offer for his belief cites some false fact if there is a true fact in the general region which would suffice in the justification we should credit that as knowledge. For instance (stealing from Weatherson’s example) if an agent justifies his belief that X by citing p&q but q is false and all the agent needs is p we should still count that as knowledge. So while I think this point is worth noting I guess I don’t feel it is of great significance because I tend to think with all of these disposition type terms (belief, knowledge etc..) there is some ambiguity which must be addressed by an application of charity.

However, my goal in this post wasn’t to attack or even respond to Weatherson’s point but to offer my very simplistic analysis of knowledge. This is something that has been floating around in my mind for awhile and it wouldn’t surprise me if it is also somewhere out in the literature but I haven’t seen it there. In short, modulo this issue of charity, why not just define knowledge as justified true belief where every necessary step along the justification is also true? (more…)

So I’m finally getting around to publishing an entry on the interface between epistemology and computability. I’m convinced if there is anything like a justification for induction it will be found in computability theory. Kevin Kelly has done some important work along this line but things are just getting off the ground and a great many questions remain unanswered. In particular while Kelly under certain assumptions has proved induction gives the ‘best’ choice of beliefs if your goal is to minimize the number of belief changes before arriving at the right theory. The question remains open if you have some other goal in mind like getting to the right theory in the shortest amount of time. Also while he touches on the notion of randomness in scientific theories I think there is much more to be said about the topic.

One question I have been puzzling over for awhile is whether allowing random phenomena in scientific theories allows us to create a theory explaining any collection of observations. That is if the world is actually too complicated to be described by a theory comprehensible to us can we make up a theory which appears to describe it by postulating randomness in the basic behavior of the universe? The answer, which was a lot simpler than I had been making it, is yes. No matter how complicated the universe turns out to be we can always come up with some theory which makes it look understandable but with some random elements.

This has some serious implications for realism and philosophy of science. In challenges the idea that the success of probabilistic theories like QM is evidence for their truth. It also illustrates the need for philosophy of science to address the question of what conditions can justify the retreat to a probabilistic theory. Unless we are to abandon the realist agenda or stipulate faith in the computable nature of the laws of nature we can’t accept a probabilistic explanation just because no deterministic explanation suffices. Thus putting the realist credentials of Quantum Mechanics in even more trouble.

I think this argument is interesting enough that it should be out in the literature so I’m particularly eager for comments. If anyone has any suggestions about how it could be fleshed out or how/if I should try to make this into a paper let me know. Any references to related literature would also be quite helpful (Kelly too since I haven’t read all his stuff). (more…)

So this is something I have been puzzled about since FEW. When Occam’s Razer forces our theory to be simple do we include the description of the initial conditions in our calculation of simplicity. That is if I have two competing theories X and Y. X is slightly simpler than Y just considering the laws of dynamics. However, Y allows a simple description of what the entire initial conditions were while in X it takes a very large number of pages to describe the initial conditions.

Troublingly there seem to be deep problems if you go either way. (more…)