May 20, 2009

The Break of the Curveball

Posted in Baseball, Law, Science, Worldview tagged , , , , at 12:34 pm by Andrew

When delving into presuppositional arguments (or the Argument from Reason, or other claims by Christians in support of mind-brain dualism), I’ll often point out that the brain we have is not cognitively reliable in precisely the sort of ways you would expect given evolution — e.g., things like Alien Hand Syndrome, optical illusions, and so on.

Thanks to Stephanie, I’ve now found the single best illustration I’ve ever seen of the way in which our brain can be fooled: the break of the curveball in baseball.

Those of us who threw curveballs know the fundamental dilemma: a classic, Blylevenesque “12-to-6” curveball appears to break much more sharply than it actually does. Part of the work of the “break” is accomplished by downward spin, and part of it is accomplished by optical illusion.

If you follow this link, you’ll see the optical illusion portion of the curveball’s break illustrated vividly. Watch the path of the spinning ball, and you can see that it travels in a straight line. Shift your focus to the blue spot, and the ball seems to be curving away from you at a drastic angle. It’s eerie!

The authors conclude:

In baseball, a curveball creates a physical effect and a perceptual puzzle. The physical effect (the curve) arises because the ball’s rotation leads to a deflection in the ball’s path. The perceptual puzzle arises because the deflection is actually gradual but is often perceived as an abrupt change in direction (the break). Our illusions suggest that the perceived “break” may be caused by the transition from the central visual system to the peripheral visual system. Like a curveball, the spinning disks in the illusions appear to abruptly change direction when an observer switches from foveal to peripheral viewing.

Just another datapoint in support of the view that our cognitive faculties are the unreliable, cobbled-together product of millions of years of evolution of the physical brain, and not some disembodied mind crafted by an almighty God.

Presuppositionalism, Part 5 (Or: What Counts As a Worldview?)

Posted in Answering Apologists, Atheism, Worldview tagged , , , , , at 9:55 am by Andrew

Continuing the discussion of presuppositionalist arguments for Christianity, one common thread seems to be that Christianity as a worldview better “explains” certain features of the world than does a naturalist/physicalist worldview. While I have previously challenged the dichotomy inherent in the argument — one need not be a naturalist/physicalist in the strong sense to be an atheist, of course — I also challenge the premise itself.

So let’s start with first principles: what does it mean to give an “explanation” for something? One need not accept Kant’s epistemology to nevertheless recognize the distinction Kant drew between (1) the analytic and (2) the synthetic. An analytic explanation is one where the explanation is derived entirely from the predicate of the proposition; put more simply, when I say, “That object is a triangle, because it has three sides,” I have given an analytic explanation. I haven’t told you anything about the triangle that you didn’t already know, because the definition of a triangle is that it has three sides.

On the other hand, if I say that object is green because it was painted with watercolors, I have given you a synthetic explanation; that is, one in which the proposition contains more information than is simply found in the predicate.

Now, to the point: it seems to me that only a synthetic proposition truly counts as an ‘explanation.’ If I say that the grass is green because it has a “green-producing nature,” that isn’t really an explanation. Ultimately I’ve told you that the grass is green because the grass is green. An explanation doesn’t just tell us that something exists; it tells us how.

And this is the problem I have with presuppositional apologetics and comparative worldview arguments. It’s just not an explanation in the synthetic sense to say “God did it.” It doesn’t tell us ‘how,’ it just gives us another name for the problem.

So my question to those of you who favor those sorts of comparative “worldview” arguments: what’s your criterion/-ia for what counts as an “explanation?”

April 23, 2009

Presuppositionalism, Part 4 (answering Cameron)

Posted in Answering Apologists, Atheism, Worldview tagged , , , , , , at 11:07 am by Andrew

(This series begins with Part 1; Part 2; and Part 3.)

In the comments to Part 1 of this series, Cameron takes up the presuppositionalist argument for the existence of God. I don’t think his answers respond to my original claim. Here’s my evaluation of Cameron’s specific arguments:
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March 3, 2009

Answering Anselm (Slick v. Dillahunty, part 3)

Posted in Answering Apologists, Atheism, Worldview tagged , , , , , , , , at 3:00 pm by Andrew

On a previous thread, commenter Anselm (probably not that Anselm, unfortunately) asks:

Doesn’t Matt D.’s strategy commit the atheist to support the Platonic objective reality (i.e., outside of spacetime) of things like numbers, logic, etc.? And isn’t that a strange position for a materialist to take (especially if he agrees with Carl Sagan that “the Cosmos is all there is, was or ever will be.” If numbers, etc. exists Platonically, then Sagan’s statement is not true, and the spaceless, timeless, immaterial reality in which theists say God exists is conceded.

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February 24, 2009

Presuppositionalism, part 2 (or: The Great Matt Dillahunty vs. Matt Slick Debate)

Posted in Answering Apologists, Atheism, Worldview tagged , , , , at 11:37 am by Andrew

One of the most important things I’m trying to do here on Evaluating Christianity is to engage in an honest dialogue with believers over what we believe and why. I’m not out to win “converts” to atheism; at most, I’m out to win converts to the notion that atheism is reasonable. At the end of the day, I’m not Christopher Hitchens — I don’t need to see theism obliterated from the face of the planet. I’d just like for the theist (and in particular, the Christian) to concede that atheism is a rational response to the world we live in.

That’s why I’ve tried to structure my Summary Case for Atheism as the kind of response I would give you if we were having a beer and a friendly chat. I don’t think the case I present is air-tight; in fact, I hope that it encourages people to raise criticisms and questions.

Now I understand that other people — both theists and atheists — have different objectives. At the extreme opposite end of the spectrum from this blog is presuppositionalism, a school of apologetics built on definitional wordplay, strategic argumentation and deliberate obfuscation. It’s a polysyllabic version of what Greta Christina calls the “Shut Up, That’s Why” school of apologetics. At the end of the day, the presuppositionalist’s goal is to “win” his debate, not listen to what you have to say. (If you don’t believe me, check out this handbook from one particularly obnoxious presuppositionalist.)

So that’s the context for this week’s episode of The Atheist Experience, which featured a continuation of the discussion/debate on presuppositionalism that I talked about last week. I have to say that Matt Dillahunty (the regular host of the Atheist Experience) gave perhaps the most interesting refutation of TAG I have ever heard. It’s pretty much the exact opposite of how I would have approached it, which I think turned out to be the near-optimal strategy. The unorthodox nature of Matt D.’s responses clearly threw Matt Slick (the presuppositionalist apologist) off of his game such that by the end of the 48-minute exchange, Slick was left with nothing more than belligerently repeating a nonsense question. Here’s my take:

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February 20, 2009

Presuppositionalism

Posted in Answering Apologists, Atheism, The Bible, Worldview tagged , , , , , , at 2:20 pm by Andrew

During the last 20 minutes of last week’s episode of The Atheist Experience — a consistently outstanding show, if you haven’t seen it — a fellow named Matt Slick from CARM (a Christian apologetics website) called in to the show armed with his presuppositional Transcendental Argument for God (“TAG”).

Let’s take a look at the underlying arguments.
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