Richard Carrier Refutes Certain Evolutionists

Creation vs. Evolution : Richard Carrier Refutes Certain Evolutionists · somewhere else : Carrier on Tacitus

I once asked my natural science teacher at junior high school how he knows Big Bang happened or Evolution happened. Or Abiogenesis.

Or how he knew Solar System arose out of a whirl of gas getting hotter as whirling closer.

Or perhaps even how he knew Solar System was working on Newtonian mechanics.

Well, the reply I got was basically : "we are here, if it didn't work, we wouldn't be".

I had an objection which he broke off my trying to voice in class. Before you guess which one it is, here is Richard Carrier for you:

The probability that the evidence exists given that we are observing it, and the probability that the evidence would exist given that a particular event happened in the past, are not the same probability.

One immediate simplification I would make is:

The probability a given piece of evidence exists that we observe (1/1) and the probability that it is evidence of a particular explanation rather than another (not 1/1) are not same probability.

The observation of a piece of evidence is not a substitute for good logic about what it is evidence about.

Now, this latter is not exactly what Richard Carrier is saying, but what he is saying is one way of finally coming at this.

What he is saying is somewhat more intricate, I'll give that too, and also (though external to this blog) answer his anti-Christian application of it:

And accordingly, FoE, despite saying P(e) is always 1 because “that’s the evidence we have,” correctly shows on screen that this is not true for the meningitis testing. He posits for his example that the probability of e, “a positive test result,” is 0.5% when you don’t have meningitis (aka ~M) and 99.5% if you do have meningitis (aka M); and he posits a base rate of having M of 1 in 1000, which means a prior probability of 0.001, or 0.1%, one tenth of one percent. And that means P(e), the probability of a positive test result “whether or not” you have M, is not 100% but in fact [P(“positive test result for M”|M) x P(base rate of M)] + [P(“positive test result for M”|~M) x P(base rate of ~M)], or, as he correctly shows on screen, (0.995 x 0.001) + (0.005 x 0.999) = (0.000995) + (0.004995) = 0.00599 (or about 0.6%). Which is nowhere near 1 (aka 100%).

One therefore would never say the probability of a positive test result “whether or not you have meningitis” is 100%. Because, in his own example, it’s 0.6%! And FoE seems to know this, as that’s what he shows on the screen. But he doesn’t connect the two examples, so he never notices his mistake in saying P(e) equals 1. The really weird thing here is that if he really thinks P(e), the whole denominator of every Bayesian equation, is always 1 because we always “have the evidence we have,” then you don’t need the denominator at all. The probability of anything is then just P(e|h) x P(h). That should have clued him in that he was making an error in his statement here. I will charitably assume he misspoke and didn’t really mean to say that.

Otherwise, he is confusing two completely different probabilities, and to help anyone else from making that mistake even if he didn’t mean to, remember this:

The probability that the evidence exists given that we are observing it, and the probability that the evidence would exist given that a particular event happened in the past, are not the same probability.

So, for example, if assessing the evidence of a murder, FoE found blood on the accused, he could rightly say “the probability that the accused is bloody, given that I observed and verified the accused is bloody” is 1 (or near enough; there is always some nonzero probability of still being in error about that, but ideally it will be so small a probability we can ignore it). But that doesn’t answer how the blood got there. What we want to know is: What is the probability that the accused is bloody given that they murdered the victim? And then, what is the probability that the accused would be bloody (= that they will test positive for meningitis / that the accounts of Jesus we have would be written when and as we have them) whether or not they murdered the victim (= whether or not they have meningitis / whether or not Jesus existed)?

That is not going to be 1. The blood could be their own; it doesn’t follow that the blood is from the victim. Or the blood could be there because they tried to rescue the victim, not because they murdered them. It doesn’t even follow that every time someone murders someone, they get or keep the victim’s blood on them. Like a positive meningitis test, many people test positive, whether or not they have meningitis. Moreover, many test negative, whether or not they have it. Similarly, many a biography is written of men, whether or not those men existed. So P(e) is frequently not 1. And in fact whenever it is 1, that means there is no evidence for the hypothesis at all.

I disagree with Richard Carrier's following assessment about biographies often getting written about men who never existed.

If we mean biographies of men taken by the normal first readership as historical, this is not true, and biographies of Bilbo or Frodo Baggins or of Peter, Susan, Edmund and Lucy Pevensey have by normal readers not been taken as historical (nor by me, if anyone imagining I am not a normal reader, because I keep returning to these examples, both as inspiring stories and because they fit this point).

What Carrier means is that biographies of Hercules, Romulus, Theseus, Aeneas, Perseus and Andromeda and quite a few more, as well as of Moses and Aaron, Joshua, King David, as well as of King Arthur, some seem ready to add Charlemagne, as well as of Adils and Rolf Kraki, Rolf's father Roar or Hrothgar and Beowulf as well as his uncle Hygelac / Hugleik / Chlochilaicus and a few more have been written without these men existing.

I think he is wrong, these men have existed, even if some details about some of them are wrong.

As a Christian I am not obliged to believe Perseus and Andromeda never lived. I am obliged to believe they did not get first raptured and then trasnformed to constellations instead of dying, and that is it. I am not obliged to believe Hercules never existed, I am obliged to believe he didn't suckle Hera in such a way as to produce the Milky Way. And while disbelief in them is not directly against any dogma, I will not do Richard Carrier the favour of diseblieving them so he can say I am inconsistent in believing Jesus and Moses.

That is on the topic of Richard Carrier's own essay, now back to the topic of this blog.

Some seem to think that the probability of:

• bodies starting to orbit each other;
• chemicals starting to combine;
• living brains including neuron exchanges

producing

• stable orbits lasting for billions of years;
• a series of cells produding cells and evolving;
• consciousness, thought, evolving into reason and language

is very close to 1, given that we observe

• stable orbits of Earth around Sun and other planets around Sun (except we don't really, since we don't observe Earth orbitting, we have also not observed the billions of years);
• life in a myriad of forms;
• the fact that we are conscious.

I think they are wrong, as Richard Carrier just told us:

The probability that the evidence exists given that we are observing it, and the probability that the evidence would exist given that a particular event happened in the past, are not the same probability.

Or, as I concluded from this:

The observation of a piece of evidence is not a substitute for good logic about what it is evidence about.

Those who deduce

• astronomy is there because bodies starting to orbit each other;
• biology is there because chemicals starting to combine;
• mind is there because living brains including neuron exchanges

are making the totally wrong assessment about the real likelihoods of what bodies starting to orbit each other, chemicals starting to combine or brains including neuron exchanges would produce on their own, and are being illogical about what can be certainly deduced from the fact that we have astronomy, biology and mind capable of observing both.

Most likely, bodies starting to orbit each other would not achieve stability, especially not if many are involved, disturbing each others' orbits, see however the discussions about this with a physicist under my post on topic, where however orbits are presumed as already in stable directions and distances:

New blog on the kid* : Newtonianly speaking, Can Earth Still Orbit Sun After 4.5 Billion Years?
http://nov9blogg9.blogspot.com/2017/01/newtonianly-speaking-can-earth-still.html

And most likely chemicals starting to combine would disintegrate, and most likely, or even certainly, if neurons in brain cells were only a matter of physics complicated a bit by chemistry, electricity and biology, mind would not be a resulting operation or quality.

And as they are wrong about their explanations being logically deduced, they are (or could at least) also be wrong about God NOT being deduced from these observations. Carrier, thanks for a neat logics lesson!

Hans Georg Lundahl
Nanterre UL
Sabbath after
II Lord's Day in Lent
18.III.2017

* It is my present main blog. Geocentrism is so unknown, they would hardly seek out a blog for Geocentrism, and in France, YEC is so unknown, French speakers hardly seek out a blog about YEC. Hence, Geocentrism in any language or Young Earth Creationism in French would rather go to my main blog than here, some exceptions.