I read an interview with a mathematician recently in which the mathematician said something kind of interesting. He said that each mathematician only has a few tricks he uses in proofs. Even the most productive rely on a few tricks to generate a lot of results. Even Erdos, even Hilbert, got most of their original results using a few basic tools. This got me wondering how well this holds for philosophers. Do most philosophers rely on just a few sorts of arguments? That probably holds for most philosophers. In reading some things by Korsgaard, I realized what one of her tricks is. This form of argument is repeated a few times. X is a conception of normativity/practical reasons/etc. that has as a consequence that some norm/reason/rule/etc. cannot be violated. But, if it cannot in principle be violated, it cannot in principle be followed either. Therefore it isn’t normative, and so not a norm/reason/rule/etc. (This should seem Wittgensteinian since she attributes a version of it to Wittgenstein in the form of his private language argument.)