The categorical imperative aims to solve the problem of what norms to pick, but goes on to try to claim universality. [...] The trick being attempted is to assume the thing we want to prove, namely universality, by assuming that satisfying our judgment of what’s best will lead to universality.
It sounds wrong to me to say that the categorical imperative “claims universality”. I’m not sure exactly what you mean by that, but it sounds as if you mean “the categorical imperative says that if a thing is permitted (according to itself), it’s universally permitted, but it also says that a thing is permitted because it’s universal or universalizable, so it’s circular”.
I don’t think the categorical imperative says that “satisfying our judgment of what’s best will lead to universality”. I think it says that it does so only in so far as we act rationally (in the Kantian sense), that, in so far as people are rational, they act according to the same law, and that this law is universal precisely because it’s based in practical reason (which every moral agent shares).
Suppose a Babyeater tries to apply the categorical imperative. Since they think eating babies is good, they will act in accordance with the norm of baby-eating and be happy to see others adopt their baby-eating ways.
You, a human, might object that you don’t like this so it can’t be universally true, yet a Babyeater would object that you not eating babies is an outrageous norm violation that will lead to terrible outcomes.
The Formula of Universal Law, which you quoted (“Act as if the maxims …”), is one of three formulations Kant gave of the categorical imperative. Another, the Formula of Humanity (“treat humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means”), clearly prohibits baby-eating, no matter what norm the agent may prefer.
They are supposedly (according to Kant) equivalent, though most Kant scholars don’t seem to treat them as if they were. I do recommend Daniel Kokotajlo’s fun decision theory app store post where he makes the case that they are in fact, sort of, equivalent.
It sounds wrong to me to say that the categorical imperative “claims universality”. I’m not sure exactly what you mean by that, but it sounds as if you mean “the categorical imperative says that if a thing is permitted (according to itself), it’s universally permitted, but it also says that a thing is permitted because it’s universal or universalizable, so it’s circular”.
I don’t think the categorical imperative says that “satisfying our judgment of what’s best will lead to universality”. I think it says that it does so only in so far as we act rationally (in the Kantian sense), that, in so far as people are rational, they act according to the same law, and that this law is universal precisely because it’s based in practical reason (which every moral agent shares).
The Formula of Universal Law, which you quoted (“Act as if the maxims …”), is one of three formulations Kant gave of the categorical imperative. Another, the Formula of Humanity (“treat humanity, whether in your own person or in the person of any other, always at the same time as an end, never merely as a means”), clearly prohibits baby-eating, no matter what norm the agent may prefer.
The Formula of Humanity isn’t equivalent to the Formula of Universal Law, though, right? Or, at least, that requires further assumptions.
They are supposedly (according to Kant) equivalent, though most Kant scholars don’t seem to treat them as if they were. I do recommend Daniel Kokotajlo’s fun decision theory app store post where he makes the case that they are in fact, sort of, equivalent.