New Bayesian Calculator

Thanks to Cam Spiers (who has produced an interesting selection of free javascript Bayesian Calculators), I have updated my own Bayesian Calculator page using the most basic of those. This might be updated again in coming months. Right now it only allows running calculations with two-digit probabilities from .01 to .99 (or 1% and 99%), so you can’t use it for odds outside that range (for example, you can’t see what happens when the prior is 1 in 1,000 or 1 in 1,000,000 or when a consequent is even closer to 100% than 99%). But future versions of the page might have those features.

For people new to the whole idea of Bayes’ Theorem and Bayesian reasoning, you should first check out my talk at Skepticon last year: Bayes’ Theorem: Lust for Glory! For a more thorough treatment (using historical reasoning as a running example), which is also aimed as much as possible at lay readers, there is now of course my book: Proving History: Bayes’s Theorem and the Quest for the Historical Jesus.

A Correction and Rebuttal

Two scholars I have criticized lately have responded to my critiques and this fact is important enough for a brief note here. The first is Dr. Ralph Kenna, whom I took to task in various ways in Bad Science Proves Demigods Exist! Though his rebuttal largely skews reality and does not adequately defend the bad science in his paper–as I demonstrate in my response–he rightly criticizes me on two points: my opening line was misleadingly facetious, and I misrepresented one of their arguments.

I apologized and made corrections to the article. Those consisted of one line at the end of the first paragraph, which now reads:

To be fair, they only claim to have evidence “the societies” and “some of the events” in them are true, not the entire stories as wrote. But really they don’t.

And a rewrite of one paragraph later in the article, which now reads (new material in bold):

Certainly Beowulf is based on real historical persons and contexts (Wikipedia has a nice summary), but Beowulf himself is by all accounts a fictional character inserted among them, to play out a supernatural drama that obviously has no basis in history (no monster was terrorizing the lands that required finding a special young warrior named Beowulf to gather a band of men to hunt it down). This is actually admitted by Kenna and Mac Carron, so I should not take them to task for that (as I did in the original draft of this critique). But the general fact of it illustrates that any character could be similarly inserted, possibly thereby undetected. This tale appears to be a Nordic (and possibly Christian-influenced) adaptation of Virgil’s Aeneid. Like the Aeneid, if in Beowulf any ancillary (non-central) character was invented to fill out the story, would Kenna and Mac Carron’s method be able to detect it? I don’t see how. We can only confirm the historicity of its characters by other, more traditional methods; and by that method, we have.

That last sentence not being a correction but just a restatement of my original overall point, transitioning to the next paragraph.

Lester Grabbe likewise responded to my criticism of him in my review of Is This Not the Carpenter?, his chapter being the only one I found so terrible I had to take it substantially to task. His rebuttal was wholly inept, and my response reconfirms that everything I said in this case was correct. No corrections warranted.

Groovy Documentary Atheism

Let me convince you to help fund a movie. This is the year for positive, uplifting atheist documentaries. (Well, actually, next year. They are being made now. They’ll probably be out then.) Two are already nearly in the can, The Scarlett Letter and Coming Out in America. Letter (directed by John Jennings) focuses on atheist leaders (not solely, but largely) and explores their lives and philosophy and the growing movement of organized atheism in America and what’s driving it (as you’ll see in the trailer, I was interviewed and will likely be among those featured in it). Out (directed by Christophe Fauchère) focuses on the goals and challenges of atheists “coming out” as atheists and dealing with the backlash from friends, family, coworkers, and community, and why more and more atheists are doing it, especially in colleges and high schools. Two great documentaries I am definitely looking forward to.

But there is another that might get made, if the filmmaker can raise the money to do it. And I think if you can help, you definitely should. It’s Hug an Atheist, and it sets itself apart from those other two films in ways that make it yet another film I really want to see, if only we can find enough financial supporters to make it possible. It will be directed by Sylvia Broeckx, a cool Belgian girl living in the UK, and that is unique feature number one: she comes from a background of European culture that simply sees nothing like the hostility to atheism we do over here, and she has become increasingly appalled by it (her trailer exemplifies what I mean, as does her accompanying mission statement). She will be able to give us a nuanced compare-and-contrast point of view between how it is and how it could be, informed by her foreign background and point of view.

But unique feature number two is even more important: [Read more…]