Most people will recognise the above reference. It’s to the infamous Omnipotence Paradox; can God (or other allegedly omnipotent being, if you prefer; when my father introduced me to it as a child, it was by way of Mr Impossible from the Mr Men books) make a stone so heavy that he can’t lift it? Various answers have been put forward to this over the years; one of them, several years ago, came from my daughter.

We were at dinner. I can’t remember at all how old my daughter was, except that it was some years back and she’s now twelve. Maybe seven? Maybe not. I forget how this came up, but my husband decided to ask the children the version of the paradox that comes up in Babylon 5: can God make a puzzle so difficult that he can’t solve it? (The character in the show includes that it’s ‘us’; humans and, given the show’s context, assumedly intelligent aliens as well.)

“Well,” Katie suggested, “he could make the puzzle so that it changes him so that then he can’t solve it.”

My husband and I exchanged the sort of look you exchange when your primary-school-aged child has just solved a centuries-old philosophical puzzle. (On the unlikely off-chance that you have not personally had occasion to encounter that look, it’s basically “Did that just happen?”) He asked her the more traditional version of the puzzle, and, of course, she figured out how her answer would fit; God designs a rock that has the property of causing him to lose the ability to lift the rock. I don’t want to brag, but my daughter is pretty darned smart.