Kevin DeYoung wrote a blog post called Less Than Meets the Eye where he lists six ways of arguing badly and explains them. I was glad to see this one. I’ve heard the Galileo thing so many times if I read it one more time I’m likely to go out the window.

If you insist that God created the world out of nothing by the word of his mouth or that homosexual behavior is sinful you’re bound to have someone bring up Galileo and slavery. The argument usually goes like this: “I can’t believe you are holding to these outdated beliefs. Sure, you think the Bible is on your side, but Christians used to think the sun went around the earth, and Christians used to defend slavery from the Bible.” The idea is: “Don’t be too confident. We’ve been wrong before, so you are probably wrong now.”

I can’t recall how many times I’ve heard this line of thinking, but it’s roughly equal to the number of rainy days in Seattle. And yet for all its frequency, this argument proves nothing more than that Christians have interpreted the Bible incorrectly in the past (leaving aside whether the usual Galileo and slavery trump cards are as historically well-suited as people think). But the fact that Southerners were sure the Bible supported chattel slavery does not mean we can’t be sure of anything. In fact, the “what about slavery” argument is self-defeating because it assumes that we do know for certain that slavery is wrong. So there are things can be sure of after all.

Read the whole post.