|By Raphael - Stitched together from vatican.va, Public Domain, |
I told Johnny that he should change one sentence that he wrote on his second-grade homework assignment. He had written,"The sun is the biggest star in the solar system." But the sun is the only star in the solar system, so that sentence doesn't mean much.
But of course, the original statement, in a mathematical sense, is true. It's not very helpful, but it's true. I mean, let's say the sun won first place in the sculpture category of the community art show. Even if it was the only entry in its category, it would still have won the contest.
Our dinner conversation that night went something like this:
Me: "Well, saying that the sun is the biggest start in the solar system is true—because it's the only star in the solar system—but it's kind of silly. I mean, what if my teacher told me to write about my family, and I wrote, 'All of my husbands work at NASA, and Owen is my biggest husband'?"
Everyone laughs and laughs.
I go on, "And Rosemary [who is not married] could also say truthfully that all of her husbands work at NASA. That statement is mathematically true."
Owen questions this, but then has an "aha" moment when he realizes that you can say that all members of the empty set are *fill in the blank,* and the statement is always true.
"Well, it's mathematically true, but not linguistically true," he says.
Four-year-old Ezekiel is quiet during the whole exchange. Finally, he says, "Daddy, daddy, I have a math problem. All of my macaroni and cheese has a cousin, and the cousin's name is . . . Glasses!"