Challenging naturalism - with logic

Every now and then I stop fiddling about in youtube and wrapping yarn around a hook to raise my sights to ponder life's big questions, and I thought this article was interesting. I dredged it up from the NY Times Opinionator. It's written by Professor of Logic at Oxford University, as a response to those who duck challenges to Naturalism. Here's an excerpt you might like to keep up your sleeve for the next watercooler conversation:

We can formulate the underlying worry as a sharp argument against the extreme naturalist claim that all truths are discoverable by hard science. If it is true that all truths are discoverable by hard science, then it is discoverable by hard science that all truths are discoverable by hard science. But it is not discoverable by hard science that all truths are discoverable by hard science. “Are all truths discoverable by hard science?” is not a question of hard science. Therefore the extreme naturalist claim is not true.