I agree that certainly some evolution would follow from your premises (1) and (2). But imagine that we also have independent evidence that Earth is 1 million years old. In that case, I’d be forced to say that the Theory of Evolution can’t account for the evidence of life we observe, given mutation rates, etc. This is the sort of thing I am worried about when I say I haven’t looked at the evidence. As far as I know there isn’t any contradictory evidence of this sort, but there may be specific challenges that aren’t well-explained. Creationists like to cite irreducible organs and claim that those exist (i.e. where it can’t evolve from anything that has any evolutionary advantage) and are contrary to the theory. I know about this objection, but it would be a lot of work to truly evaluate it in depth.
As far as having an alternative: this isn’t necessary. I’d be reluctant to go with “God did it”, so I’d be fine with “the theory explains 95% of the evidence, and about the other 5% we don’t know yet, and we have no better theory”.
Just realised you’re the post author, so: Thanks for posting this, it’s something I’ve wondered about in relation to myself, as well. :)
1: No tentacles
But imagine that we also have independent evidence that Earth is 1 million years old.
This reminds me of something Eliezer once said—”How would I explain the event of my left arm being replaced by a blue tentacle? The answer is that I wouldn’t. It isn’t going to happen.” We do not observe a young (even 10^6) Earth, and by suggesting the possibility of one as counterevidence against the strength of the ‘a priori’ reasoning I advocated, you must be smuggling in a circular assumption that young Earth models have significant probability.
Your argument as I understand it is roughly that since my a priori reasoning would fail in young Earth scenarios, then that reasoning is unreliable. But if our prior for young Earth scenarios is extremely low, then it will only very rarely happen that my reasoning will fail in that particular way. Therefore for your argument to go through, you would have to place a high prior probability on young Earth scenarios.
To put it another another way: If observing a young Earth would be evidence against my a priori reasoning, then by conservation of expected evidence, our actual observation of a non-young Earth must be evidence in favour of that reasoning.
People in a modern day situation, and LW’ers in particular, are better placed to understand that ‘naturalistic’ explanations are preferable, and that magic ones should incur huge complexity penalties. Therefore we should have low priors on young Earths, because most of our probability will be concentrated in models where intelligent life arises from nonintelligent (hence slow) processes as opposed to intelligent (e.g. God) processes.
Moreover, the more intelligent the process that generated us, the more we push the explanatory buck back onto that process. God is an extreme case where the mystery of the apparent improbability of human intelligence is replaced with the mystery of the apparent improbability of divine intelligence. But even less extreme cases like superhumanly (but still decidedly ‘finitely intelligent’) entities simulating us incurs a penalty for passing the explanatory buck back. Natural selection is so elegant and formidable because it is an existing behaviour of what we already observe.
2: Insanity screens off charity
Creationists like to cite irreducible organs
If—even before accepting evolution by natural selection—you can put an extremely high probability on creationists spewing objections like ‘irreducible organs’ regardless of the veracity of evolution by natural selection, then you can pretty much write off the counterarguments of creationists, because your observation of creationists making these arguments is extremely weak evidence that there is anything to these counterarguments. Now, this is circular if your only reason for not taking creationists seriously is that they are wrong natural selection/irreducible organs, but there’s ‘any number’ of other reasons to suspect creationists are engaging in motivated cognition.
The same way that if natural selection provides a substantial portion of the explanation of evolution, then, you need look no further, if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I think you are interpreting my comments with too much emphasis on specific examples I give. Sure, Earth being 1 million years old is unlikely, but there could be some equally embarrassing artifact or contradictory evidence. I can’t give a realistic example because I haven’t studied the problem—that’s my whole point. You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing. Besides, surely, if someone runs cryptological analysis software on the DNA of E. Coli, and get back “(C) Microsoft Corp.”, that would rather undermine the theory?:)
In actuality, for me it comes down to trust: I expect if there was important contradictory evidence, someone would report it. Creationists think that biologists are all in on a conspiracy to hide the truth and would not change their mind if they see such evidence—that is rather unlikely from my point of view. That is to say, like you, I am not spending a lot of time evaluating the underlying facts because I think one side is reliable and the other is not. But it feels wrong to me to ignore evidence because of who says it. I understand your argument that you expect some evidence to be presented by them and that makes it unnecessary to examine it, but I think you are wrong. You do have to examine it in case it turns out that their evidence is in fact overwhelming your prior. They could be right in a specific case even if it’s unlikely. Even a stopped clock is right twice a day.
You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing.
Let’s be a bit more precise. Evolution is a mechanism. It works given certain well-known preconditions. The fact that it works is not contested by anyone sane.
What actually is contested by creationists is that the mechanism of evolution is sufficient to generate all the variety of life we see on Earth and that it actually did, in fact, generate all that variety. *That* claim is falsifiable -- e.g. by showing that some cause/mechanism/agency other than evolution played an important part in the development of life on Earth.
You’re steelmanning the creationist position. That’s fine, but by saying “what actually is contested...” you’re also asserting that creationists only believe your steelman and not the position it’s a steelman of.
There may be some who do.
However, there are plenty of creationists who think that evolution cannot work. Some of their arguments include: “Evolution would mean order comes out of disorder, which is impossible” and “Evolution is a violation of the Second Law of Thermodynamics.”
I think it better be true that both of these are falsifiable (and they both are). I agree that the former is overwhelmingly likely and no one I’d care to talk to disputes it. In any event I am only talking about the latter. The fact that it completely explains the variety of life on Earth is the very thing I am accepting on faith, and that’s what I don’t like.
if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I’ve just discovered Argument Screens Off Authority by EY, so it seems I’ve got an authority on my side too:) You can’t eliminate an argument even if it’s presented by untrustworthy people.
I agree that certainly some evolution would follow from your premises (1) and (2). But imagine that we also have independent evidence that Earth is 1 million years old. In that case, I’d be forced to say that the Theory of Evolution can’t account for the evidence of life we observe, given mutation rates, etc. This is the sort of thing I am worried about when I say I haven’t looked at the evidence. As far as I know there isn’t any contradictory evidence of this sort, but there may be specific challenges that aren’t well-explained. Creationists like to cite irreducible organs and claim that those exist (i.e. where it can’t evolve from anything that has any evolutionary advantage) and are contrary to the theory. I know about this objection, but it would be a lot of work to truly evaluate it in depth.
As far as having an alternative: this isn’t necessary. I’d be reluctant to go with “God did it”, so I’d be fine with “the theory explains 95% of the evidence, and about the other 5% we don’t know yet, and we have no better theory”.
Just realised you’re the post author, so: Thanks for posting this, it’s something I’ve wondered about in relation to myself, as well. :)
1: No tentacles
This reminds me of something Eliezer once said—”How would I explain the event of my left arm being replaced by a blue tentacle? The answer is that I wouldn’t. It isn’t going to happen.” We do not observe a young (even 10^6) Earth, and by suggesting the possibility of one as counterevidence against the strength of the ‘a priori’ reasoning I advocated, you must be smuggling in a circular assumption that young Earth models have significant probability.
Your argument as I understand it is roughly that since my a priori reasoning would fail in young Earth scenarios, then that reasoning is unreliable. But if our prior for young Earth scenarios is extremely low, then it will only very rarely happen that my reasoning will fail in that particular way. Therefore for your argument to go through, you would have to place a high prior probability on young Earth scenarios.
To put it another another way: If observing a young Earth would be evidence against my a priori reasoning, then by conservation of expected evidence, our actual observation of a non-young Earth must be evidence in favour of that reasoning.
People in a modern day situation, and LW’ers in particular, are better placed to understand that ‘naturalistic’ explanations are preferable, and that magic ones should incur huge complexity penalties. Therefore we should have low priors on young Earths, because most of our probability will be concentrated in models where intelligent life arises from nonintelligent (hence slow) processes as opposed to intelligent (e.g. God) processes.
Moreover, the more intelligent the process that generated us, the more we push the explanatory buck back onto that process. God is an extreme case where the mystery of the apparent improbability of human intelligence is replaced with the mystery of the apparent improbability of divine intelligence. But even less extreme cases like superhumanly (but still decidedly ‘finitely intelligent’) entities simulating us incurs a penalty for passing the explanatory buck back. Natural selection is so elegant and formidable because it is an existing behaviour of what we already observe.
2: Insanity screens off charity
If—even before accepting evolution by natural selection—you can put an extremely high probability on creationists spewing objections like ‘irreducible organs’ regardless of the veracity of evolution by natural selection, then you can pretty much write off the counterarguments of creationists, because your observation of creationists making these arguments is extremely weak evidence that there is anything to these counterarguments. Now, this is circular if your only reason for not taking creationists seriously is that they are wrong natural selection/irreducible organs, but there’s ‘any number’ of other reasons to suspect creationists are engaging in motivated cognition.
The same way that if natural selection provides a substantial portion of the explanation of evolution, then, you need look no further, if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I think you are interpreting my comments with too much emphasis on specific examples I give. Sure, Earth being 1 million years old is unlikely, but there could be some equally embarrassing artifact or contradictory evidence. I can’t give a realistic example because I haven’t studied the problem—that’s my whole point. You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing. Besides, surely, if someone runs cryptological analysis software on the DNA of E. Coli, and get back “(C) Microsoft Corp.”, that would rather undermine the theory?:)
In actuality, for me it comes down to trust: I expect if there was important contradictory evidence, someone would report it. Creationists think that biologists are all in on a conspiracy to hide the truth and would not change their mind if they see such evidence—that is rather unlikely from my point of view. That is to say, like you, I am not spending a lot of time evaluating the underlying facts because I think one side is reliable and the other is not. But it feels wrong to me to ignore evidence because of who says it. I understand your argument that you expect some evidence to be presented by them and that makes it unnecessary to examine it, but I think you are wrong. You do have to examine it in case it turns out that their evidence is in fact overwhelming your prior. They could be right in a specific case even if it’s unlikely. Even a stopped clock is right twice a day.
Let’s be a bit more precise. Evolution is a mechanism. It works given certain well-known preconditions. The fact that it works is not contested by anyone sane.
What actually is contested by creationists is that the mechanism of evolution is sufficient to generate all the variety of life we see on Earth and that it actually did, in fact, generate all that variety. *That* claim is falsifiable -- e.g. by showing that some cause/mechanism/agency other than evolution played an important part in the development of life on Earth.
You’re steelmanning the creationist position. That’s fine, but by saying “what actually is contested...” you’re also asserting that creationists only believe your steelman and not the position it’s a steelman of.
There may be some who do.
However, there are plenty of creationists who think that evolution cannot work. Some of their arguments include: “Evolution would mean order comes out of disorder, which is impossible” and “Evolution is a violation of the Second Law of Thermodynamics.”
Sure, but we are not really talking about the creationists here, we’re talking about whether evolution is falsifiable and in which sense.
As the person who asked the question, I’d like to say that I don’t particularly care about what creationists believe either.
I think it better be true that both of these are falsifiable (and they both are). I agree that the former is overwhelmingly likely and no one I’d care to talk to disputes it. In any event I am only talking about the latter. The fact that it completely explains the variety of life on Earth is the very thing I am accepting on faith, and that’s what I don’t like.
I’ve just discovered Argument Screens Off Authority by EY, so it seems I’ve got an authority on my side too:) You can’t eliminate an argument even if it’s presented by untrustworthy people.
Argument screens off authority only if you have already considered the argument. This doesn’t mean you should consider all arguments by anyone.