First I was like, "oh no, another one claims that faith could be rational without showing why it is". Then I parsed the simulation part and clicked "upvote" because it showed me a new and scary possibility.

In the year 2020, cousin_it downloads some software for running predictor sims. He wants to optimize his future conduct - test which particular minor mind-hack would be the most beneficial, given his individual psychological makeup. So he runs many ancestor sims of himself poisoned with different irrational mind-hacks to see who wins in the past. I am one such sim, poisoned in an unknown manner; what should I do?

Times like these I regret that I can't write good sci-fi in English because it's not my first language.

This post does not seem to contribute much. As nawitus pointed out, this post does a good enough job of distinguishing between instrumental and epistemic rationality.

While it seems obvious that in some cases, a false belief will have greater utility than a true one (I can set up a contrived example if you need one), it's a devil's bargain. Once you've infected yourself with a belief that cannot respond to evidence, you will (most likely) end up getting the wrong answer on Very Important Problems.

And if you've already had your awakening as a rationalist, I'd like to think it would be impossible to make yourself honestly believe something that you know to be false.

I think the mistaken assumption here is that you can actually choose to have faith. Certainly you can choose to repeat the words "I have faith". You can even say those words inside your head. You can even attend religious services. That is not the same as actually believing in your religion.

I think this essentially is what Orwell called "Doublethink", and it seems to explain much of the religious behavior I personally have seen.

This post is based on the (very common) mistake of equating religious practice and religious faith. Religion is only incidentally about what you believe; the more important components are community and ritual practice. From that perspective, it is a lot easier to believe that religion can be beneficial. What you think about the Trinity, for instance, is less important than the fact that you go to Mass and see other members of your community there and engage in these bizarre activities together.

There is an enormous blindspot about society in the libertarian/rationalist community, of which the above is just one manifestation.

I know some individuals that I believe would be worse off if they were to have a crisis of faith and lose their religion. And while I can't be sure and have never run any tests to find out, I think that they really believe, not just with belief in belief. By the way, none of these are particularly intelligent people.

But I have a hard time imagining someone intelligent and rational who would be better off deceiving themself and gaining faith. Adopting a religion where you are allowed to fake it (like Risto suggests) would almost certainly be better. Sometimes I adopt foma to help me through the day, but I don't take them seriously.

Of course, it's easy to imagine situations where they would be better off mouthing faith, such as kidnap and interrogation by fundamentalist terrorists, or daily life in a lot of societies (past and present) where rationality is undervalued. But I don't think that this is what you mean.

According to these definitions, it could be instrumentally rational to be religious for some subset of people, but not epimestically rational.

I don't think simulations help. Once you start simulating yourself to arbitrary precision, that being would have the same thoughts as you, including "Hey, I should run a simulation", and then you're back to square one.

More generally, when you think about how to interact with other people, you are simulating them, in a crude sense, using your own mind as a shortcut. See empathic inference.

If you become superintelligent and have lots more computing resources, then your simulations of other minds themselves become minds, with experiences indistinguishable from yours, and make the same decisions, for the same reasons. What's worse, the simulations have the same moral weight! See EY's nonperson predicates.

(This has inspired me to consider "Virtualization Decision Theory", VDT, which says, "Act as though setting the output of yourself in a simulation run by beings deciding how to interact with a realer version of you that you care about more.")

Here are my earlier remarks on the simulated-world / religion parallel.

Belief in the concept of a time-continuous "self" might be an example of an article of Faith that is useful for humans.

(Most people believe in a time-continuous self anyway, they just don't realize it's something that current best physics tells us there's no evidence for the existence of.)

I didn't downvote this post, but I can't say I endorse seeing more posts like it. The concept of this post is one of the least interesting in a huge conceptspace of decision theory problems, especially decision theory problems in an ensemble universe. To focus on 'having faith' and 'rationality' in particular might seem clever, but it fails to illuminate in the same way that e.g. Nesov's counterfactual mugging does. When you start thinking about various things simulators might do, you're probably wrong about how much measure is going to be taken up by any given set of simulations. Especially so once you consider that a superintelligence is extremely likely to occur before brain emulations and that a superintelligence is almost assuredly not going to be running simulations of the kind you specify.

Instead of thinking "What kind of scenario involving simulations could I post to Less Wrong and still be relevant?", as it seems to me you did, it would be much better to ask the more purely curious question "What is the relative power of optimization processes that would cause universes that include agents in my observer moment reference class to find themselves in a universe that looks like this one instead of some other universe?" Asking this question has led me to some interesting insights, and I imagine it would interest others as well.

The basic idea is sound - If you really think religion is good/bad for X, the best proof would be to run a simulation and observe outcomes for X. I interpret the downvoting to -10 as a strong collective irrational bias against religion, even in a purely instrumental context.

The corollaries are distracting.

Don't some interpretations of neopagan magic have a bit of the same idea as the religion thing here? The idea is that there isn't assumed to be any supernatural woo involved, the magic rituals just exist as something that an observing human brain will really glom onto, and will end up doing stuff that it is able to but otherwise might not have done.

I think Eric S. Raymond and Alan Moore have written about magic from this outlook. Chaos magic with its concept of belief as a tool might also be relevant.

I'm not convinced that the religious have any particular advantages wrt akrasia and such things.

A conversion is sure to give you a great deal of energy & willpower temporarily, but ultimately that's a finite resource.

The main advantage the religious have is supportive community. That is where rationalists really fall down, although I think LW is a step in the right direction.

I think the question "Is it rational to be religious?" is one that deserves critical attention and testing, but talk of ancestor simulations completely demolishes the point. Any entity capable of creating an actual ancestor simulation--a fully-modeled "Matrix" populated with genuinely human-equivalent sentient Sims--is an entity for whom the results of such a test would be irrelevant and obsolete. The premise, that some form of Faith might be useful or even necessary for rational humans to maximally act in accordance with their values, is not applicable for a posthuman being.

The technology for creating a real ancestor simulation would almost certainly exist in a context of other technologies that are comparably advanced within their fields. If the computer power exists to run a physics engine sufficient to simulate a whole planet and its environs, complete with several billion human-level consciousnesses, the beings who possess that power would almost certainly be able to enhance their own cognitive and psychological capacities to the point that Faith would no longer be necessary for them, even if it might be for us here and now, or for the Sims in the ancestor simulation. A creator of ancestor simulations would for all practical intents and purposes be God, even in relation to his/her own universe. With molecular nanotechnology, utility fogs, programmable matter, and technologies we can't even imagine, conjuring a burning bush or a talking snake or a Resurrection would be child's play.

Proposing ancestor simulations as a way to test the usefulness of Faith is like saying, "Let's use a TARDIS to go watch early space-age planets and see if rockets or solar sails are the best way for us to explore the universe!"

On the other hand, we do already possess computer platforms that are fairly good at emulating other human-level intelligences, and we routinely create plausible, though limited world-simulations. These are "human brains" and "stories," respectively. So one way to partially examine and test to determine whether or not it could be rational to be religious would be to write a story about a rational person who adopts a Faith and applies it to maximally operate according to his or her values.

Then, present the story to people who believe that Faith, and people who don't. Is the story itself believable? Do the other minds processing the simulation (story) judge that it accurately models reality? Unfortunately this method cannot simultaneously generate billions of fully-realized simulated lives so that a wide variety of Faiths and life-circumstances under which they are used can be examined. Instead, the author would have to generate what they consider to be a plausible scenario for a rational person adopting a Faith and write a genuinely believable story about it. To serve as an effective test, the story would have to include as many realistic circumstances adverse to the idea as possible, in the same way that the secret to passing the 2-4-6 Test is to look for number sets that produce a "no." It could not be written like a fictional Utopia in which the Utopia works only because everyone shares the author's beliefs and consistently follows them.

Eliezer's story Harry Potter and the Methods of Rationality does a mirror-opposite of this, providing a story-test for the question, "Would the Sequences still be applicable even under the extreme circumstance of being catapulted into the Harry Potter universe?" Some of the best moments in this story are where Harry's rationalist world-view is strained to the utmost, like when he sees Professor McGonagall turn into a cat. A reader who finds the story "believable" (assuming sufficient suspension-of-disbelief to let the magic slide) will come away accepting that, if the Sequences can work even in a world with flying broomsticks and shape-shifting witches, they'll probably work here in our rather more orderly and equation-modelable universe.

So, a "So-And-So and the Methods of Faith" story might, if well-written, be able to demonstrate that Faith could be a valid way of programming the non-rational parts of our brain into helping us maximally operate according to our values.

Another method of testing (perhaps a next step) would be to adopt the techniques of Chaos Magic and/or Neuro-Linguistic Programming and try out the utility of Faith (perhaps testing different Faiths over set periods of time) in one's own life. Or better still: get the funding for a proper scientific study with statistically-sufficient sample sizes, control-groups, double-blind protocols, etc..

This post definitely has problems, but given the fairly interesting discussion it appears to have prompted, does not seem to deserve being in the minus-double digits.

I think the central point is that the practical value of faith is more of an empirical question than a logical one. The central problem, of course, is that for a real person to accept some propositions on faith requires a (likely significant) dent in their overall rationality. The question is not about the value of faith, but about the tradeoffs made to obtain it; a complexity which is not really addressed here, and which may prove so entwined as to be impossible to arrive at deliberately.

In other words, once you've chosen a certain amount of rationality, many paths of faith are closed to you. Conversely, once you've chosen a certain amount of faith, some levels of rationality are closed to you.