Like many pseudoscientists, Denyse O’Leary doesn’t understand how evidence works:

I’ll bet she’s right, in exactly this sense: if there turns out to be a ninth planet, Denyse O’Leary will interpret it as support for fine tuning. There is very little that advocates for intelligent design don’t interpret as support for their worldview. What do you want to bet that if there turns out not to be a ninth planet, she won’t interpret that as evidence against fine tuning?

We already know that O’Leary believes the universe is fine-tuned for life, so clearly she thinks a solar system with eight planets is fine-tuned. Now she’s telling us that a solar system with nine planets would also be fine-tuned. Just how finely-tuned is the solar system if it doesn’t matter how many planets there are?

Advocates for intelligent design regularly claim that it is science (and sometimes, absurdly, that evolution is religion), and in some cases they have scientific backgrounds. In many cases, though, they betray a deep misunderstanding of how science actually works. Scientists make and (often) test predictions because the outcomes allow us to evaluate which hypothesis is likely to be true. O’Leary has got that part right: she has floated a testable prediction (a ninth planet exists) to support a hypothesis (the universe is fine-tuned). But she has misunderstood a critical point: in order for a prediction to have value, its support for a given hypothesis should depend on its outcome.

This failure is common in the intelligent design community. I have documented it before under the heading “Heads I win, tails you lose.” Here’s a partial list of mutually exclusive outcomes where both possibilities support intelligent design:

If evolving multicellularity is hard, that supports intelligent design. If evolving multicellularity is easy, that supports intelligent design.

If humans and chimps are genetically similar, that supports intelligent design. If humans and chimps are genetically quite different, that supports intelligent design.

If life is common in the universe, that supports intelligent design. If life is rare in the universe, that supports intelligent design.

This is pure motivated reasoning. Intelligent design advocates are telling us upfront that whatever the evidence turns out to be, they will interpret it as support for what they already believe.