Tautologies and Rhetoric

Today, I read PZ Myers's response to this argument against evolution. PZ does a fine job of taking it down, but there is one point I'd like to make, and this is something that shows up in many places. Egnor says that evolution is a tautology and is therefore false or fallacious. The problem is that a tautology is not a fallacy. In fact, by definition, a tautology is always true.

That's what a tautology is. Something that's always true, no matter what. For example, if x is true, then x is true. That statement is always true whether or not x is. It's just not interesting. There's no real claim or anything there. A tautology is only interesting when it gets combined with something else, which is what Darwin did with evolution by combining the tautology of "survivors survive" with variation and heritability.

And of course that doesn't mean that tautologies can't be used fallaciously. They're frequently used to sneak in a fallacy such as begging the question. But pointing out a tautology doesn't in and of itself show an argument to be fallacious.

AlDraw, Version 2.1

Well, it's been more than a year since I announced I was working on AlDraw 2.0. Now, 2.1 is out. The coolest thing: now it does colors. Look!

There are also a few other new features. It does copy and paste, too, although that's a bit complicated since it handles scaling and rotation in addition to translation. So now, a year later, I've hit all the big things on the to-do list. There are still plenty of little things to work on. More pictures can be found here.

The Problem with The Bible as a Moral Guide

Well, one of them, anyway. The problem with using The Bible as a moral guide is that it can be, and has been, used to support pretty much everything.

The bible has been used to support slavery. It's also been used to oppose it. It's been used to show that premarital sex is evil, and also to show that it's alright. It's been used to support women's rights and oppose them. People have used it to argue for and against gay marriage. People have even made biblical arguments for and against environmentalism. The only thing I can think of that the bible has only been used to support one side of is bestiality. That's not saying a lot.

How are you supposed to find out what's right when the Bible supports and opposes whatever you want resolved?


This video makes about the same points from around 11:00 to 11:50. It also makes many other good points.