My 13-year-old son is attending philosophy camp and one of his homework assignments is to come up with some objections to Kantianism. In a previous conversations I suggested a ridiculous counter-example for Kant's universalizability principle ("Act only according to that maxim whereby you can at the same time will that it should become a universal law.") As my son generously appreciates my jokes more than anyone else does, it stuck with him and he's thinking of using it. I don't actually understand the universalizability principle well enough to defend it from my joke, though I can't imagine there wouldn't be a pretty simple argument against it. I found this, but I was hoping for something more concise. Here is the example:
- If I think it's ok for me to pick my nose, then I should consider it permissible for everybody to pick my nose.
Can anyone give me a one or two sentence defense against this example?
Edit. Rephrasing as a maxim and contradiction in response to @ChristopherE's answer and comments:
- When I'm bored, the first thing I should do to pass the time is pick my nose, which would be hard to do in a world in which everyone picked my nose when they were bored.
(The whole question, of course, is reminiscent of the classic joke maxim: "You can pick your friends and you can pick your nose, but you can't pick your friend's nose," as well as a variation on it I heard a couple decades ago: "You can pick your friends and you can pick your nose, but you can't legislate morality.")